And if you think its only Yahoo doing this, you're dreaming.
Yahoo Inc last year secretly built a custom software program to search all of its customers' incoming for specific information provided by U.S. intelligence officials, according to people familiar with the matter.
The company complied with a classified U.S. government demand, scanning hundreds of millions of Yahoo Mail accounts at the behest of the National Security Agency or FBI, said three former employees and a fourth person apprised of the events.
Some surveillance experts said this represents the first case to surface of a U.S. Internet company agreeing to an intelligence agency's request by searching all arriving messages, as opposed to examining stored messages or scanning a small number of accounts in real time.
Experts said it was likely that the NSA or FBI had approached other Internet companies with the same demand, since they evidently did not know what email accounts were being used by the target. The NSA usually makes requests for domestic surveillance through the FBI, so it is hard to know which agency is seeking the information.