Why are some u. s. citizens opposed to the usa patriot act?

The Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act, better known as the USA PATRIOT Act, is a law that was originally enacted by President Bush in 2001 following the 9/11 attacks. The act stated that the United States government could take certain actions in order to thwart the threat of terrorism, such as the use of the NSA to track and tap people suspected of being a terrorist. Many oppose this act because it threatens to violate the Constitutional rights to privacy and fair treatment. It also can be a source of racial discrimination, as they suspected someone who looked Muslim or Middle Eastern, even if they were not; this led to many activities against Sikh Americans who were thought to be Muslims.