FISA was created by the U.S. Congress based on the recommendations of the Senate's Church Committee, which was convened in 1975 to investigate illicit activities and civil rights abuses by the federal intelligence community.

On December 16, 2005, The New York Times reported that the Bush administration had been conducting surveillance against U.S. citizens without specific approval from the FISA court for each case since 2002.

[27] Elizabeth Goitein, a co-director of the Liberty and National Security Program of the Brennan Center for Justice at the New York University School of Law, has criticized the court as being too compromised to be an impartial tribunal that oversees the work of the NSA and other U.S. intelligence activities.

[37] These court-approved policies allow the NSA to do the following:[38][39] Jameel Jaffer, the ACLU's deputy legal director, said in light of revelations that the government secured telephone records from Verizon and Internet data from some of the largest providers that safeguards that are supposed to be protecting individual privacy are not working.

[19] Elizabeth Goitein, co-director of the Liberty and National Security Program at the Brennan Center for Justice in New York, wrote in the Wall Street Journal that when courts make mistakes, the losing party has the right to appeal and the erroneous decision is reversed.

"[19] According to The Guardian, "The broad scope of the court orders, and the nature of the procedures set out in the documents, appear to clash with assurances from President Obama and senior intelligence officials that the NSA could not access Americans' call or email information without warrants".

The Fisa court plays no role whatsoever in reviewing whether the procedures it approved are actually complied with when the NSA starts eavesdropping on calls and reading people's emails.

The only oversight for monitoring whether there is abuse comes from the executive branch itself: from the DOJ and Director of National Intelligence, which conduct "periodic reviews ... to evaluate the implementation of the procedure".

At a hearing before the House Intelligence Committee Tuesday afternoon, deputy attorney general James Cole testified that every 30 days, the Fisa court is merely given an "aggregate number" of database searches on US domestic phone records.

Representative Jerrold Nadler, challenged Cole's defense of the program's constitutionality, and he said the secrecy in which the court functioned negated the validity of its review.

"The fact that a secret court unaccountable to public knowledge of what it's doing ... may join you in misusing or abusing the statutes is of no comfort whatsoever", Nadler said.

[41] Orin Kerr, a law professor at George Washington University, said the secrecy that comes along with national security makes it difficult to evaluate how the administration carries out the wide authority Congress has given it.

"[19] In July 2013, The New York Times published disclosures from anonymous government whistleblowers of secret law written by the court holding that vast collections of data on all Americans (even those not connected in any way to foreign enemies) amassed by the NSA do not violate the warrant requirements of Fourth Amendment to the U.S. Constitution.

The special needs doctrine was originally established in 1989 by the Supreme Court in a ruling allowing the drug testing of railway workers, finding that a minimal intrusion on privacy was justified by the government's need to combat an overriding public danger.

[42] The court concluded that mass collection of telephone metadata (including the time of phone calls and numbers dialed) does not violate the Fourth Amendment as long as the government establishes a valid reason under national security regulations before taking the next step of actually examining the contents of an American's communications.

[42] Under the new procedures passed by the U.S. Congress in the FISA Amendments Act of 2008, even the collection of metadata must be considered "relevant" to a terrorism investigation or other intelligence activities.

[42] A secret ruling made by the court that redefined the single word "relevant" enabled the NSA to gather phone data on millions of Americans.

According to Supreme Court rulings, a phone call's content is covered by the Constitution's Fourth Amendment, which restricts unreasonable searches, but the other types of data are not.

[48] "Relevant" has long been a broad standard, but the way the court is interpreting it, to mean, in effect, "everything", is new, said Mark Eckenwiler, a lawyer who until December 2012 was the Justice Department's primary authority on federal criminal surveillance law.

[48] Given the traditional legal definition of relevant, Timothy Edgar, a former top privacy lawyer at the Office of the Director of National Intelligence and the National Security Council in the Bush and Obama administrations, noted it is "a fair point" to say that someone reading the law might believe it refers to "individualized requests" or "requests in small batches, rather than in bulk database form".

[48] In June 2013, a copy of a top-secret warrant, issued by the court on April 25, 2013, was leaked to London's The Guardian newspaper by NSA contractor Edward Snowden.

[58] The document leaked to The Guardian acted as a "smoking gun" and sparked a public outcry of criticism and complaints[49][59][60] that the court exceeded its authority and violated the Fourth Amendment by issuing general warrants.

Most of these defenses involve the 1979 Supreme Court decision Smith v. Maryland which established that people do not have a "reasonable expectation" of privacy for electronic metadata held by third parties like a cellphone provider.

This notion said that when a person has voluntarily disclosed information to a third party – in this case, the telephony metadata – the customer no longer has a reasonable expectation of privacy over the numbers dialed nor their duration.

[70] Rulings for the plaintiff in cases brought by the ACLU on September 10 and 12, 2013, prompted James Clapper to concede that the government had overreached in its covert surveillance under part 215 of FISA and that the Act would likely be amended to reflect Congressional concern.

[71] The American Civil Liberties Union, a customer of Verizon, asked on November 22, 2013, a federal district court in Lower Manhattan, New York to end the NSA phone call data collection program.

The ACLU argued that the program violated the U.S. Constitution's guarantees of privacy and information as well as exceeding the scope of its authorizing legislation, Section 215 of the Patriot Act.

[73] On 12 January 2017, BBC journalist Paul Wood reported that, in response to an April 2016 tip from a foreign intelligence agency to the CIA about "money from the Kremlin going into the US presidential campaign", a joint taskforce had been established including representatives of the FBI, the Department of the Treasury, the Department of Justice, the CIA, the Office of the Director of National Intelligence and the National Security Agency.

According to Wood, this application was rejected, as was a more narrowly focused request in July, and the order was finally granted by a different FISA judge on 15 October, three weeks before the presidential election.

[79] On April 11, The Washington Post reported that the FBI had been granted a FISA warrant in the summer of 2016 to monitor then-Trump foreign policy adviser Carter Page.