Based on the search results, the key points regarding FISA and warrantless surveillance are:

1. FISA was originally passed in 1978 to allow the government to collect foreign intelligence information involving communications with "foreign powers" and "agents of foreign powers".[3][5]

2. However, the USA PATRIOT Act in 2001 expanded FISA to allow the government to obtain personal records of ordinary Americans from libraries and the internet, even without a connection to terrorism.[5]

3. Recent amendments to FISA, such as the Protect America Act, have further authorized the government to use FISA to conduct warrantless surveillance on Americans, bypassing constitutional protections.[5]

4. There is significant controversy and criticism around these expansions of FISA, with civil liberties groups like the ACLU arguing that FISA is being used to make an "end-run around the Constitution" and allow warrantless spying on American citizens.[5]

5. The search results indicate that while FISA was originally intended for foreign intelligence gathering, it has been repeatedly expanded to enable warrantless domestic surveillance, which has drawn strong opposition from privacy advocates.[3][5]

So in summary, yes the search results suggest that FISA has been used to allow warrantless wiretapping and surveillance of American citizens, despite the original intent of the law. This has been a major source of controversy and criticism.[5]

Sources
[1] Modified surveillance bill clears key House hurdle after failing earlier this week https://edition.cnn.com/2024/04/12/politics/house-vote-fisa-reauthorization/index.html
[2] The FISA reauthorization bill has finally passed the House. - The Verge https://www.theverge.com/2024/4/12/24128585/the-fisa-reauthorization-bill-has-finally-passed-the-house
[3] House Republicans confront fight over FISA reauthorization | CNN Politics https://www.cnn.com/2024/04/09/politics/house-republicans-fisa-reauthorization/index.html
[4] House clears a hurdle on reauthorizing FISA spy ... - ABC News https://abcnews.go.com/Politics/house-clears-hurdle-reauthorizing-fisa-spy-program-after/story?id=109162400
[5] The Foreign Intelligence Surveillance Act - News and Resources https://www.aclu.org/documents/foreign-intelligence-surveillance-act-news-and-resources