The dreamers, brains and cranks who built the Internet hoped it would be a tool of liberation and knowledge. Last week, an altogether bleaker vision emerged with new revelations of how the United States government is using it as a monitoring and tracking device, David Streitfeld and Quentin Hardy write in The New York Times.

In Silicon Valley, a place not used to second-guessing the bright future it is eternally building, there was a palpable sense of dismay. The first mystifying thing for some here is how the leading companies â€" including Microsoft, Google, Yahoo, Apple and Facebook â€" apparently made it easier for the National Security Agency to gain access to their data. Only Twitter seems to have declined.

The companies deny directly working with the government on the project, called Prism. But they have not been exactly eager to talk about how they are working indirectly and where they would draw the line.

Entrepreneurs around Silicon Valley are publicly urging more disclosure.