THE USA PATRIOT ACT OF 2001
The USA PATRIOT is an act of United States congress that was assented into law on October 26, 2001. It is an acronym that stands for Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001. It represents the US government’s primary legislative response to terrorist attacks of September 11th. This Act focused on significant reduction in restrictions in law enforcement agencies’ collecting of intelligence within the united states; expanding the secretary of the treasury’s authority to regulate financial transactions, specifically those involving foreign individuals and entities; and broadening the discretion of law enforcement and immigration authorities in keeping in custody and deporting immigrants suspected of terrorism- related acts.
The law which governs the material support of terrorism is contentious causing an infringement of freedom of association. The Humanitarian Law Project, objected to the provision prohibiting expert advice and assistance to terrorists and filed a suit against the U.S. government to have it declared unconstitutional. They succeeded, and a Federal Court found that the law was vague enough to cause a reasonable person to guess whether they were breaking the law or not. Thus they found it violated the First Amendment rights of U.S. citizens, and struck it down
One of the biggest controversies involved the use of National Security Letters by the FBI to allow them to search telephone, email, and financial records without a court order. In November 2005, it was reported that the FBI had issued so many National Security Letters that they had obtained one million financial, credit, employment and health records from the customers of targeted Las Vegas businesses. Selected businesses included casinos, storage warehouses and car rental agencies.
The constitutionality of National security letters was challenged in court in April 2004; it was argued that the National Security Letters violated the First and Fourth Amendments of the U.S. Constitution because the USA PATRIOT Act 2001 failed to give an outline of any legal process whereby a telephone or Internet company could oppose the letter in court. The court agreed, and found that because the recipient of the letter could not challenge it in court it was agreed that it was unconstitutional. Congress later tried to reinstitute this in a reauthorization Act, but because they did not do away with the non-disclosure provision the Federal court again found National security letters to be unconstitutional for they prohibited courts from engaging in significant judicial review.

Reference:
Mailman et al (2002): Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism (USA Patriot Act) Act of 2001: An Analysis. Newark, NJ and San Francisco, CA: Matthew Bender & Co., Inc. (a member of the LexisNexis Group)