Bush’s eavesdropping program was explicitly anticipated in 1978, and made illegal by FISA. There might not have been fax machines, or e-mail, or the Internet, but the NSA did the exact same thing with telegrams.Two decades ago the Senate Intelligence Committee chaired by Sen. Frank Church determined that the National Security Agency (NSA) Project Shamrock, which intercepted telegrams and analyzed them, was inappropriate domestic spying. NSA terminated that program. Congress passed the Foreign Intelligence Surveillance Act (FISA), saying the executive had to get warrants for such sigint, and creating a FISA court to issue such warrants. This is the same court that the current administration bypassed, ordering the NSA to collect information without warrants on communications involving U.S. citizens in the U.S.
— Project Shamrock, by Bruce Schneier, 29 December 2005
As Bruce points out, this isn’t about terrorism; it’s about the separation of powers mandated in the U.S. Constitution. What’s the point of fighting terrorists if you’re going to give away what you’re fighting for?