Live Video of Christopher Dorner Manhunt

Live video from the CBS News affiliate KCAL TV of the manhunt for Christopher Dorner.

As our colleague Jennifer Media reports, law enforcement officials were involved in a shootout on Tuesday afternoon with Christopher J. Dorner, the former Los Angeles police officer who is the target of the largest manhunt in Los Angeles Police Department history, officials said.

Several television channels dispatched helicopters and news crews to the scene and broadcast live images from above the area of the San Bernardino Mountains where the man thought to be the former officer was reportedly surrounded by officers following the exchange of gun fire.

At one stage in the live coveage from the CBS News affiliate KCAL TV, an exchange of fire (and a fleeting obscenity) could be heard clearly on the air as one of the station’s journalists, Carter Evans, reported from the scene.

Audio recorded by Buzzfeed from a live video stream of a CBS/KCAL TV broadcast during a gun battle on Tuesday in the San Bernardino Mountains.

Shortly after that report, the CBS affiliate broke away from their reporter on the scene for an interview with a man who pretended to be an official with the United States Fish and Wildlife Service, but was, in fact, a prank caller who made a reference to the Howard Stern show before being cut! off.

Ronnie the Limo Driver is Howard Stern’s head of security. That is who the prank caller was referring to.

â€" Alex Weprin (@alexweprin) 12 Feb 13

At a news conference in Los Angeles just after 3 p.m. Pacific Time, a spokesman for the L.A.P.D. appealed to the media to not show any close shots of their officers on the scene, since the suspect could be watching the live television coverage.

Apple Chief Hints at Shareholder Rewards to Come

Investors want more cash from Apple.

Timothy D. Cook, Apple’s chief executive, wasn’t ready to give it to them on Tuesday. But recent history and Mr. Cook’s tendency to foreshadow events before they occur strongly suggest he will reward them soon.

Speaking for the second consecutive year in at a Goldman Sachs technology investor conference, Mr. Cook said Apple’s management team and board were discussing how to return more of the company’s enormous stockpile of cash to shareholders.

If those words sound familiar, it’s because Mr. Cook said almost the same thing a year ago at the Goldman Sachs conference. A month later, the company announced a plan to return more than $45 billion to shareholders over three years in the form of dividends and share repurchase..

That plan only served to slow the swelling of Apple’s cash hoard, not to reduce it. Last year around this time, Apple had nearly $100 billion in cash. Now it has around $137 billion.

“We do have some cash,” Mr. Cook said at the Goldman conference on Tuesday, in a moment of deliberate understatement that set off chuckles from his audience.

Some investors â€" like the hedge-fund manager David Einhorn â€" are cranky that Apple’s cash is sitting around earning so little interest.

Mr. Cook said Apple had looked at making some big acquisitions but never seriously enough to follow through on the deals. With its cash, Apple could afford one Amazon or two Facebooks and still have billions in spare change.

Instead, Apple buys smaller companies, mostly for their talent or intellectual property, Mr. Cook said. He said Apple has averaged a! bout one acquisition every other month for the last three years.

How to send more cash to shareholders is the tricky part. Much of Apple’s cash is generated overseas and can’t be paid out to shareholders without being subject to repatriation taxes. In a recent research note, Toni Sacconaghi, an analyst at Bernstein Research, said  Apple could not meaningfully increase its return of cash to shareholders without paying the taxes or issuing debt.

While the latter option sounds nonsensical for a company with as much cash in the bank as Apple, a number of cash-rich technology companies, including Microsoft and Cisco, have issued debt, taking advantage of low interest rates. Mr. Sacconaghi suggested that the most attractive option for Apple shareholders would be for the company to borrow money, perhaps in the range of $50 billion to $100 billion, and use it to buy back stock or increase the dividend. He said increasing the return of cash was critical for Apple to attract a new class of dividend-hngry value investors as the company’s growth slows. Apple’s shares have declined about 33 percent since their high in September.

Mr. Cook called a lawsuit filed against the company by Mr. Einhorn, president of Greenlight Capital, a “silly sideshow.”

Mr. Einhorn has claimed that a change Apple is proposing to make to its corporate charter would limit the option of returning more cash to shareholders through the issuing of preferred stock. Apple has said that even with the charter change, it could issue preferred stock with shareholder approval.

Mr. Cook danced around the rumors that Apple would create an inexpensive iPhone for emerging markets, where income levels and a lack of subsidies by wireless carriers have put the company’s smartphone out of reach for many consumers. But he noted Apple’s history of coming up ! with crea! tive new products, like the iPod shuffle and the iPad Mini, that appeal to budget-minded shoppers.

“The only thing we’ll never do is make a crappy product,” he said. “That’s the only religion we have.”

Why Is Verizon Reviewing Smartphone Apps

Android phones have access to hundreds of thousands of apps, but not all are worth buying or downloading. Verizon Wireless is stepping in to call out the ones that are good and bad.

In a blog post, Verizon said that it had what it called a team of experts evaluate apps in the Android app store. It primarily assessed the apps for how they will affect a mobile device. Verizon lists its favorite apps as well as some “high-risk” Android apps that can cause problems like rapid battery draining, exposed privacy or unexpected high data usage.

The list of Android apps that fall under the high-risk category includes some of the most popular mobile apps, like Doodle Jump, Draw Something and Fruit Ninja. The reviewers knock Doodle Jump, because when the app is running, it keeps the device from going into sleep mode, and, if left untouched, it drains the battery three times faster than normal. They make simila complaints about the other games.

“Not really a ‘high risk’ in my book,” said Igor Pusenjak, a creator of Doodle Jump, in an e-mail, regarding Verizon’s assessment of his app.

Conversely, Verizon gives Angry Birds high marks for security, battery consumption and data usage.

Sounds like a noble effort on Verizon’s part, but why is the carrier reviewing apps in the first place After all, Verizon would benefit from apps using excess data, because that would result in higher cellphone bills for customers.

David Samberg, a Verizon spokesman, said that it behooved the company to inform customers on how apps affect their smartphones because an app that behaves badly can detract from the entire customer experience. And dissatisfied customers might complain to the carrier, not the app maker.

“If you have a problem and your data usage is through the roof, the app developer isn’t going to get that phone call,” he said. “Verizon is going to get that phone call.â! €

“We don’t want there to be any surprises,” he added. “We want people to be educated on what they’re e downloading and how it’s going to affect their device.”

Australian Report on Israel\'s \'Prisoner X\' Suggests Melbourne Man Was Mossad Agent

The Australian Broadcasting Corporation reported on Tuesday that a man referred to in Israel as “Prisoner X,” who was jailed and died under mysterious circumstances in 2010, might have been an Australian-born Israeli who worked for Israel’s secret service, the Mossad.

According to the ABC, an unnamed source “with connections to Israel’s security establishment” claimed that the prisoner â€" whose detention and suicide at the high-security Ayalon Prison outside Tel Aviv was briefly reported on an Israeli news site in December 2010 despite a gag order â€" was named Ben Alon. That same month, the network reported, a man from suburban Melbourne, Ben Zygier, who had emigrated to Israel 12 years ago and changed his name to Ben Alon, died in Israel.

Although the Australian state broadcaster published video and a complete transcriptof the 28-minute report online, Israeli news sites removed articles describing the ABC investigation after editors were summoned to an emergency meeting by Prime Minister Benjamin Netanyahu’s office, Reuters reported.

The Israeli media/censor killed press coverage of the ██████ █ affair today. Want to know what it’s about http://t.co/cdV7N7BS

â€" Michael Omer-Man (@MikeOmerMan) 12 Feb 13

As the Israeli journalist Noam Sheizaf explained in a post for the Tel Aviv news blog +972, reporters in Israel! have been trying to skirt the gag order for more than two years. On Tuesday, he reported:

The Israeli media published short stories based on the Australian piece this morning. Usually, the Israeli military censor allows Hebrew stories on secret issues if they are based on foreign sources. The assumption is that the information has already been made available, so there is little point in keeping it secret. Around noon the stories on the dead prisoner disappeared from the Haaretz, Globes and Walla sites.

An urgent meeting with the editors of the Israeli papers was later called by the Prime Minister’s Office. The so-called “editors’ committee” is an informal Israeli institution in which newspapers editors were given access o secret information in exchange for refraining from publishing it. According to a report in Haaretz, the meeting was called regarding an affair which “severely embarrasses” a government institution or person.

Trevor Bormann, the ABC journalist who led the investigation broadcast Tuesday on the network’s current affairs program “Foreign Correspondent,” explained what Israeli journalists are up against in his report:

Foreign Correspondent has obtained details of a gag order issued in late June 2010 under the case name “Israel versus John Doe.” In it, Judge Hila Gerstl, of the Petach Tikva District Court bans any public mention or hint of Prisoner X, Mr X, cell number 15 in `c Prison, the conditions there, or anything about being held in that cell. As an indication of how sensitive th! e issue w! as, the Judge ruled that even mention of the existence of the order was prohibited.

Concerns about censorship, and the reported secret detention of an Israeli citizen who somehow managed to hang himself in a high-security prison, prompted a stream of questions for Israel’s justice minister on Tuesday in the Knesset, Israel’s Parliament, Haaretz reported.

“I cannot answer these questions because the matter does not fall under the authority of the Justice Minister,” the justice minister, Yaakov Ne’eman, said. “But there is no doubt that if true, the matter must be looked into.”

As Mr. Bormann noted in his ABC the report, relations between Israel and several other nations became strained in early 2010 when it emerged that “Mossad had used the identities of dual nationals living in Israel, including four Australians,” on forged passports used by suspects in the assassination of a Hamas official in Dubai.

During its investigation, Mr. Bormann added, the ABC’s producers lodged a freedom of information request with Australia’s Department of Foreign Affairs and Trade asking for any documents relating to Ben Zygier, also known as Ben Alon.” In response, he reported:

D.F.A.T. told us there were documents relating to his imprisonment and death but we weren’t entitled to see them because their release could have a substantial adverse impact on the proper and efficient conduct of consular operations. But curiously in their response to me D.F.A.T. referred constantly to a Mr. Allen. When I asked for clarification, a department official told me that Ben Zygier, also known as Ben Alon, also carried an Australian passport bearing the name Ben Allen.

Writing on Twitter, Israeli bloggers and journalists have tried to draw atention to the Australian report, sharing a copy of program posted on YouTube and photographs of the man identified as Ben Zygier by the ABC.

All Israeli media sites are now trying to hint to their readers about the Prisoner X story, following the removal of items by censorship

â€" noam sheizaf (@nsheizaf) 12 Feb 13

Apparently this is prisoner X: https://t.co/QV7MLDmX context http://t.co/DWUyAm4j

â€" noam sheizaf (@nsheizaf) 12 Feb 13

A New Home, and a New App, for San Francisco\'s Exploratorium

Next month the Exploratorium, the hands-on science museum created by the physicist Frank Oppenheimer four decades ago, will open its doors at its new location at Pier 15 on the San Francisco waterfront.

On Monday, however, it will be possible to get a virtual preview of the museum’s learn-by-doing approach with the introduction of “Sound Uncovered,” the second free iPad application developed by the Exploratorium staff. In 2011, its first effort, “Color Uncovered,” drew an enthusiastic audience, and was ultimately downloaded more than one million times, at one point rising to second place among all free applications on Apple’s app store charts.

“That was great because that’s right in there with Facebook and things like that,” said Robert Semper, a physicist who is the Exploratorium’s executive associate director.

In each case the programs try to convey a physical experience that is similar to the exhibitions found on the floor of the highly interactive museum.

âœOne of the beauties of our group is that we get to pull from the physical museum, we get to pull from the science expertise of our content people on staff, we get to pull from the teachers who have figured out all of these cool experiments,” said Jean Cheng, project director of the online engagement group at the Exploratorium. “It’s like this endless buffet of options and you have to decide, ‘How much can we do’”

Both applications explore illusions as a means of explaining different qualities and properties of light and sound. “We’re pretty familiar with optical illusions, but auditory illusions are much less common,” she said.

Each application is divided into chapter-like experiments. In Sound Uncovered, for example, an experiment titled “Find the Highest Note” challenges the user to find the highest note, playing tricks with pitch and volume. By playing sounds on an onscreen keyboard it is possible to explore how the auditory system works and understand pattern re! cognition.

Other experiments in Sound Uncovered make it possible to record your voice and play it backward; illusions that make it possible for your eyes to fool your ears; as well as a hearing test making it possible to determine how your hearing compares to that of others.

One of the strengths of the applications compared with the actual museum is that people are more willing to experiment and try things out when they feel more at ease and less as if they performing in public.

About a half million people each year visited the Exploratorium at its original site at the Palace of Fine Arts. That number is expected to expand dramatically with the opening of the Pier 15 location, which is one of the cornerstones of a revamped San Francisco waterfront. This year, the America’s Cup sailboat races will be held at the waterfront.

The online reach of the museum will still extend far beyond the actual museum. Currently there are about 12 million visitors each year to the Exploratorium Web site.

This post has been revised to reflect the following correction:

Correction: February 12, 2013

An earlier version of this post misspelled the name of the Exploratorium.

How Frothy Is the Tech Boom

Lots of start-ups in Silicon Valley aren’t just getting rich on paper. They are cashing out, long before they get to the public market.

The New York Times recently published an article on the large number of Silicon Valley companies that are not publicly traded, but that are valued at $1 billion or more by their investors. That is make-believe wealth, as many people commenting on the story noted. A company only finds its total value if it is purchased, or has an initial public offering; everything else is a combination of its funding history, a best guess compared with its peers, and a little bit of hope.

A couple of recently published reports, however, back the idea that tech companies are seeing historically rich valuations. They also offer some insights into where this is headed.

CB Insights, which looks at venture funding and acquisitions, published a rundown of private tech company mergers and acquisitions in 2012. There were 2,277 deals last year, it said.

That was up, the company’s chief executive, Anand Sanwal, said in a separate e-mail, from 1,895 private acquisitions in 2011. “Our expectation, given the cash strength of tech companies and that technology is ‘encroaching’ on other industries, is that 2013 should be a bigger year than 2012,” Mr. Sanwal wrote.

Of 331 deals last year in which the purchase price was announced, however, just eight were for $1 billion or more. If most of the companies The Times wrote about are going to live up to their $1 billion valuations, they probably won’t do it through M.&A.

There were 13 deals between $500 million and $1 billion. So if you can get your company halfway to a billion dollars in value, you’ve got a decent shot at getting it all the way there.

Another way to generate w! ealth without an I.P.O. is to sell shares on the secondary market. The primary vehicle for this, Second Market, recently published its year in review.

The firm won’t say how many companies’ shares it is now selling, though it does say that in 2012 it worked with more companies than ever, and listed eight different types of tech businesses it is handling, including gaming, education and financial services.

That, along with the fact that software and consumer electronics were both bigger, in total transaction size, than social media like Twitter or Facebook (which was still private in the early part of last year, and was regularly the biggest business for Second Market), indicated that this shadowy private market is increasing in size and complexity.

Second Market also operates a kind of wish list, in which potential buyers can indicate their appetite for different industries. This was lss encouraging. Over $2 billion was nominally interested in consumer Web and social media businesses. Software and gaming was second, with just $191 million, and mobile was third with $99 million.

The broad hunger on the investment side, it would seem, is still for unproven social businesses. If that is the case, the great number of enterprise hardware, software and mobility companies with valuations over $1 billion will probably have to conduct an I.P.O. to get their cash.

The company also publishes a list of companies that are being closely followed by Second Market users. This can serve as a proxy for what will soon be hot (or frothy) in valuations, since this is where the private money wants to go. The leader in the fourth quarter of 2012 was Shapeways, a 3-D printing marketplace.

The median market capitalization among Second Market’s companies was $569 million. Call that a final note of hope. As the CB Insights report suggests, when it ! comes to ! acquisitions, the first half-billion is definitely the hardest.

A New Home, and a New App, for San Francisco\'s Exploritorium

Next month the Exploritorium, the hands-on science museum created by the physicist Frank Oppenheimer four decades ago, will open its doors at its new location at Pier 15 on the San Francisco waterfront.

On Monday, however, it will be possible to get a virtual preview of the museum’s learn-by-doing approach with the introduction of “Sound Uncovered,” the second free iPad application developed by the Exploritorium staff. In 2011, its first effort, “Color Uncovered,” drew an enthusiastic audience, and was ultimately downloaded more than 1 million times, at one point rising to second place among all free applications on Apple’s app store charts.

“That was great because that’s right in there with Facebook and things like that,” said Robert Semper, a physicist who is the Exploritorium’s executive associate director.

In each case the programs try to convey a physical experience that is similar to the exhibitions found on the floor of the highly interactive museum.

“ne of the beauties of our group is that we get to pull from the physical museum, we get to pull from the science expertise of our content people on staff, we get to pull from the teachers who have figured out all of these cool experiments,” said Jean Cheng, project director of the online engagement group at the Exploritorium. “It’s like this endless buffet of options and you have to decide, ‘How much can we do’”

Both applications explore illusions as a means of explaining different qualities and properties of light and sound. “We’re pretty familiar with optical illusions, but auditory illusions are much less common,” she said.

Each application is divided into chapter-like experiments. In Sound Uncovered, for example, an experiment titled “Find the Highest Note” challenges the user to find the highest note, playing tricks with pitch and volume. By playing sounds on an onscreen keyboard it is possible to explore how the auditory system works and understand pattern reco! gnition.

Other experiments in Sound Uncovered make it possible to record your voice and play it backward; illusions that make it possible for your eyes to fool your ears; as well as a hearing test making it possible to determine how your hearing compares to that of others.

One of the strengths of the applications compared with the actual museum is that people are more willing to experiment and try things out when they feel more at ease and less as if they performing in public.

About a half million people each year visited the Exploritorium at its original site at the Palace of Fine Arts. That number is expected to expand dramatically with the opening of the Pier 15 location, which is one of the cornerstones of a revamped San Francisco waterfront. This year, the America’s Cup sailboat races will be held at the waterfront.

The online reach of the museum will still extend far beyond the actual museum. Currently there are about 12 million visitors each year to the Exploritorium Web site.

Square Enters Another Coffee Chain, Blue Bottle

To pay for Burundian coffee and olive oil rosemary shortbread, customers of Blue Bottle, the small coffeehouse chain in California and New York, can now use Square.

Square, the mobile payments company that wants to abolish cash, lets anyone with a cellphone or tablet to accept credit cards. It also has a GPS-enabled app called Square Wallet, which lets customers pay by saying their names to a cashier, without even pulling out a card. Retailers can use Square Register to do things like print kitchen tickets and track inventory.

Square has three million individuals and businesses using it to accept payments, including Starbucks, and has earned a valuation from investors of $3.25 billion. Yet many businesses and shoppers have never heard of it, and its app for paying without showing a card has been slow to catch on.

The key to success for Square might be small chains like Blue Bottle. They multiply the revene of a single small, local business, and unlike large chains, they are more likely to tear out their existing point-of-sale systems and replace them with an iPad and a Square device.

Starbucks, for instance, began accepting payments using some Square services last year, but kept its point-of-sale system, so stores do not use the Square device.

Revenue from Square businesses with multiple accounts is seven times what it was six months ago, according to the company. Other small chains using Square include Pitango Gelato in the Washington, D.C., area, Amy’s Ice Creams in Austin and Cartel Coffee Lab in Arizona.

“We love seeing local businesses thrive to become national successes,” Jack Dorsey, Square’s co-founder and chief executive, said in a statement.

Coffee shops like Blue Bottle have been formative fo! r Square’s business. Sightglass Coffee Roasters in San Francisco and Café Grumpy in New York have been testing grounds for Square’s products. Mr. Dorsey was an early investor in Sightglass.

Blue Bottle has 11 stores on both coasts. Square will start running in three of them Tuesday and the others in coming months.

The coffee company already has tech cred. Last fall, several of technology’s big names invested in the chain, including Kevin Systrom of Instagram, Kevin Rose of Digg and Google Ventures and Mike Volpi of Cisco and Index Ventures.

No word on how these small, specialty coffee chains feel about Square’s involvement with Starbucks, an archrival. (On Blue Bottle’s Web site, the company takes a jab at the giant chain, saying Blue Bottle’s founder “was weary of the grande eggnog latte and the double skim pumpkin-pie macchiato.”)

James Freeman, the founde, said in a statement, “We think about the right wood for our counters, the best beans and how we can continue to serve our customers the perfect cup of coffee as we grow. Square’s attention to detail and focus on the customer makes Square Register the right choice for our business.”

Square Enters Another Coffee Chain, Blue Bottle

To pay for Burundian coffee and olive oil rosemary shortbread, customers of Blue Bottle, the small coffeehouse chain in California and New York, can now use Square.

Square, the mobile payments company that wants to abolish cash, lets anyone with a cellphone or tablet to accept credit cards. It also has a GPS-enabled app called Square Wallet, which lets customers pay by saying their names to a cashier, without even pulling out a card. Retailers can use Square Register to do things like print kitchen tickets and track inventory.

Square has three million individuals and businesses using it to accept payments, including Starbucks, and has earned a valuation from investors of $3.25 billion. Yet many businesses and shoppers have never heard of it, and its app for paying without showing a card has been slow to catch on.

The key to success for Square might be small chains like Blue Bottle. They multiply the revene of a single small, local business, and unlike large chains, they are more likely to tear out their existing point-of-sale systems and replace them with an iPad and a Square device.

Starbucks, for instance, began accepting payments using some Square services last year, but kept its point-of-sale system, so stores do not use the Square device.

Revenue from Square businesses with multiple accounts is seven times what it was six months ago, according to the company. Other small chains using Square include Pitango Gelato in the Washington, D.C., area, Amy’s Ice Creams in Austin and Cartel Coffee Lab in Arizona.

“We love seeing local businesses thrive to become national successes,” Jack Dorsey, Square’s co-founder and chief executive, said in a statement.

Coffee shops like Blue Bottle have been formative fo! r Square’s business. Sightglass Coffee Roasters in San Francisco and Café Grumpy in New York have been testing grounds for Square’s products. Mr. Dorsey was an early investor in Sightglass.

Blue Bottle has 11 stores on both coasts. Square will start running in three of them Tuesday and the others in coming months.

The coffee company already has tech cred. Last fall, several of technology’s big names invested in the chain, including Kevin Systrom of Instagram, Kevin Rose of Digg and Google Ventures and Mike Volpi of Cisco and Index Ventures.

No word on how these small, specialty coffee chains feel about Square’s involvement with Starbucks, an archrival. (On Blue Bottle’s Web site, the company takes a jab at the giant chain, saying Blue Bottle’s founder “was weary of the grande eggnog latte and the double skim pumpkin-pie macchiato.”)

James Freeman, the founde, said in a statement, “We think about the right wood for our counters, the best beans and how we can continue to serve our customers the perfect cup of coffee as we grow. Square’s attention to detail and focus on the customer makes Square Register the right choice for our business.”

Daily Report: Where the Broadband Roams

In Tuesday’s New York Times, Edward Wyatt reports from Agate, Colo., on the $4 billion Broadband Technology Opportunities Program, part of the Obama administration’s 2009 economic stimulus effort. The aim of the grant program is to extend high-speed Internet access to parts of the country that had little or none of it because private companies said it was too expensive to build.

But local phone companies have complained about waste or unfair competition, like using some of the grants to build fiber networks where they already exist â€" including, in Colorado, in the easily accessible eastern plains that include Agate â€" rather than where they are most needed, in rural mountain towns.

Nationally, $594 million in spending has been temporarily or permanently halted, 14 percent of the overall program, and the Commerce Department’s inspector general hs raised questions about the program’s ability to adequately monitor spending of the more than 230 grants.

In Illinois, for example, a $12 million broadband grant was sanctioned when a subcontractor was caught routing fiber optic cable through neighborhoods where its project engineers lived. A $39 million grant in Arizona was suspended over questionable expenditures on travel, transactions that appeared to involve conflicts of interest and other unbudgeted activities.

In Agate, two high-speed connections already existed in a school that had been teaching students from kindergarten through 12th grade. Now the oldest students are fifth graders, and the school says the high-speed fiber optic service is of little use and beyond its means. It has requested bids for a slower-speed connection to replace it.

Agate’s third fiber optic connection was among the projects built with funds from a $100 million grant to an education consortium called Eagle-Net. The grant has been suspended sin! ce December, when officials discovered that Eagle-Net had changed nearly all of its plans for wiring the state. Four months earlier, Eagle-Net was warned about questionable spending and lack of budgetary controls, according to Commerce Department documents.

Nextdoor, a Network for Neighborhoods, Attracts Early Backer of Facebook and LinkedIn

Facebook is where people promote how cute their kids are, and LinkedIn is where they promote themselves. Nextdoor is where they promote their need to borrow a ladder.

Now Nextdoor, a San Francisco-based Web site for connecting neighbors, has something else in common with its far bigger and better known peers in the social networking trade: the same early investor.

Greylock Partners, a venture capital firm that made investments years ago in LinkedIn and Facebook, has led a $21.6 million financing round in Nextdoor. David Sze, the Greylock partner who invested in those other companies, will join Nextdoor’s board of directors.

New investors participating in the funding also include Google Ventures and Bezos Expeditions, the investment firm of Jeff Bezos, the Amazon.com chief executive, along with existing investors Benchmark Capital and Shasta Ventures. In total, the company has raised $40.2 million.

Nextdoor first opened for business in late 2011 and is now available in 8,000 neigborhoods in all 50 states. That number is more impressive when you consider that the Nextdoor networks for all of those neighborhoods were started by a person who lived in that neighborhood and then successfully recruited at least nine other neighbors to join.

Only people who actually live in a neighborhood are eligible to join the Nextdoor network for their area and everybody has to use their real identities on the site, which Nextdoor says is essential for keeping the quality of conversations on the site high.

Nextdoor verifies that you live where you say you do either by checking your credit card record, making an automated phone call to your home number or by sending a postcard to your house with a registration code on it. The company sends out 15,000 such postcards a day, according to Nirav Tolia, the chief executive of Nextdoor.

“It’s a lot of friction to join,” he said.

Mr. Tolia declined to say how many people are members of Nextdoor.

In an interview at his! office in San Francisco, Mr. Tolia showed a slide with a bar chart breaking down the most common uses for Nextdoor. Recommendations (for baby sitters, good mechanics and the like) and posts about a local break-in and other crime and safety issues are among the top two categories.

Neighbors are also using it as a hyperlocal version of Craigslist, where they send out requests to borrow shop vacs and other infrequently used items or advertise piles of bricks and other free items they’d like to get rid of. Nextdoor has revamped its Web site to make it easier for people to sort posts in their neighborhood by categories, and the company is also allowing people to post messages to adjacent neighborhood networks on Nextdoor (lost cats don’t necessarily recognize neighborhood boundaries).

Mr. Sze of Greylock said most of the connections on Facebook are between people who already have an existing relationship, but Nextdoor is connecting people who very often don’t know each other, even though they ive in close proximity. “The fascinating thing about Nextdoor is there’s this latent desire to connect with people around you,” he said.