The NSA's been around since 1952, but what the 2001 Patriot Act did was to amend the 1978 FISA law to setup secret courts to issue secret warrants to conduct secret searches, and the NSA only had to report the number of such warrants obtained per year to Congress, meaning there was no real accountability. The US Constitution allows for spying on US citizens, but there was supposed to be accountability to the Courts and Congress. Now the checks and balances are gone.