The Patriot Act is a more than 300-page document passed by the U.S. Congress with bipartisan support and signed into law by President George W. Bush on October 26, 2001, just weeks after the September 11 terrorist attacks against the United States.

Prior to the  9/11 attacks, Congress had mainly focused on legislation to prevent international terrorism. But after the April 1995 Oklahoma City bombing in which American citizens blew up a federal building, domestic terrorism gained more attention.

On April 24, 1996, President Bill Clinton signed the “Antiterrorism and Effective Death Penalty Act of 1996,” to make it easier for law enforcement to identify and prosecute domestic and international terrorists.

The law, however, didn’t go far enough for President Clinton. He’d asked Congress to give law enforcement expanded wiretap authority and increased access to personal records in terrorism cases, among other things. Congress refused, mainly because many felt loosening surveillance and records rules was unconstitutional.

All bets were off, however, after 9/11, the deadliest terrorist attack on American soil. Faced with millions of fearful voters, Congress approached U.S. Attorney General John Ashcroft’s post-9/11 recommendations with a different eye and overwhelmingly passed the Patriot Act.

According to the Department of Justice, the Patriot Act simply expanded the application of tools already being used against drug dealers and organized crime. The act aimed to improve homeland security by:

Many of the Patriot Act’s requirements were slated to expire in 2005. Whether to renew the act was passionately argued in the U.S. House of Representatives and the Senate.

Despite continued civil liberties and privacy concerns, President Bush signed the USA Patriot and Terrorism Reauthorization Act on March 9, 2006.

Depending on whom you ask or what you read, the Patriot Act may or may not have prevented terrorism.

According to a 2015 Washington Post article, the Justice Department admitted, “FBI agents can’t point to any major terrorism cases they’ve cracked thanks to the key snooping powers in the Patriot Act.”

But a 2012 report from the conservative Heritage Foundation states 50 terrorist attacks have been thwarted since 9/11, with 47 being the direct result of the work of law enforcement and intelligence agencies. They claim the Patriot Act is essential to helping law enforcement identify leads and prevent attacks.

In 2004 testimony before the United States Senate Committee on the Judiciary, FBI Director Robert Mueller said, “the Patriot Act has proved extraordinarily beneficial in the war on terrorism and has changed the way the FBI does business. Many of our counterterrorism successes, in fact, are the direct results of provisions included in the Act…”

He also stated that without the provisions in the act, “the FBI could be forced back into pre-September 11 practices, attempting to fight the war on terrorism with one hand tied behind our backs.”

Despite the supposed noble intentions behind the Patriot Act, the law is still hotly debated. Civil rights groups have claimed it violates American citizens’ Constitutional rights and allows the government to spy on them without due process, search their homes without consent and increase the risk of ordinary citizens being accused of crimes without just cause.

The federal government asserts the Patriot Act has safeguards to protect the rights of American citizens. Still, some parts of the law were found illegal by the courts. For instance, in 2015 the United States of Appeals for the Second Circuit found Section 215 of the Patriot Act could not be used to validate the bulk collection of Americans’ phone records.

To help prevent the Patriot Act from infringing on Americans’ civil liberties, President Barack Obama signed the USA Freedom Act into law on June 2, 2015.

The act ended the bulk collection of all records under Section 215 of the Patriot Act and allowed challenges to national security letter gag orders. It also required better transparency and more information sharing between the United States Foreign Intelligence Surveillance Court and the American people.

Some ways the USA Freedom Act is meant to strengthen national security are:

Despite the act’s efforts to protect civil liberties, its critics believe it doesn’t go far enough. The benefits of the Patriot Act and the USA Freedom Act to national security will undoubtedly continue to be weighed against the potential intrusion on Americans’ privacy and their civil rights.

Bush Signs Patriot Act Renewal. CBS News.

FBI Admits No Major Cases Cracked with Patriot Act Snooping Powers. Washington Post.

Fifty Terror Attacks Foiled Since 9/11: The Homegrown Threat and the Long War on Terrorism. The Heritage Foundation.

H.R.3162 – Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism (USA PATRIOT ACT) Act of 2001**.** Congress.gov.

N.S.A. Collection of Bulk Call Data is Ruled Illegal. The New York Times.

Surveillance Under the Patriot Act. ACLU.

The USA Patriot Act: Preserving Life and Liberty. Department of Justice Website.

USA Freedom Act. House of Representatives Judiciary Committee.

William J. Clinton, XLII President of the United States: 1993-2001, Statement on Signing the Antiterrorism and Effective Death Penalty Act of 1996. The American Presidency Project.