The U.S. government is spying on its own citizens' online activities. The FBI was able to suss out and shut down the anonymous black market Silk Road. Even the Internet-within-the-Internet called the Tor network -- the most secretive way to browse the Web -- is being monitored by the National Security Agency.
Strong passwords and encrypted email services were never truly enough to protect users' online privacy. But recent revelations about government surveillance even throw into doubt the effectiveness of far-out measures of data encryption used by the most careful people surfing the Web.
Silk Road serves as a prime example. It operated as a hidden service on Tor, an anonymizing tool that helps users and sites keep their identities secret. Everyone buying and selling drugs, weapons and other illicit items on the site thought they couldn't be tracked.
But federal agents managed to track down a computer server Silk Road used, and the FBI monitored more than 1.2 million private communications on the site.