FISA was passed by Congress largely as a response to the revelations of the Church Committee, chaired by then-Sen. Frank Church of Idaho. The Church Committee uncovered numerous examples of U.S. intelligence-gathering agencies perpetrating despicable acts -- plotting assassinations of democratically elected foreign leaders, unlawfully maintaining stores of chemical and biological agents, and using wiretaps to spy on people who posed no danger to others.
Given that our president has been bypassing the FISA court, now is a good time for all Americans to learn (or refresh their memories) about the Church Committee's findings. This website to is a good place to start.
I'll sign off with this quote from Jeffrey H. Smith, the former general counsel of the CIA, who said this about FISA and similar laws:
"I think it is wrong to conclude in a simplistic fashion that these rules and regulations, which have been designed to constrain the activities of an intelligence agency in a democracy ... I think it's a mistake to immediately conclude that those rules need to be thrown out just because of [the 9/11] intelligence failure."