SAN FRANCISCO — 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.

In Silicon Valley, a place not used to second-guessing the bright future it is eternally building, there was a palpable sense of dismay.

“Most of the people who developed the network are bothered by the way it is being misused,” said Les Earnest, a retired Stanford computer scientist who built something that resembled Facebook nine years before the inventor of Facebook was born. “From the beginning we worried about governments getting control. Well, our government has finally found a way to tap in.”

The technology world has always strived to keep Washington at a certain arm’s length. Regulation would snuff out innovation, the entrepreneurs regularly cried. Bureaucrats should keep their hands off things they do not understand, which is just about everything we do out here.