Civil liberties are often defined as the protection of the individual from the unrestricted power of the government. One important doctrine that outlines our civil liberties is the Bill of Rights.
On September 11, 2001, 19 four commercial airplanes were hijacked and used in a plan to commit acts of terror in New York City, NY and Washington, DC. Both towers of the New York trade center as well as the Pentagon were hit. A fourth attached aimed at the White House was thwarted by heroic passengers, who crashed the plane in a field in Pennsylvania. The results of these attacks were a loss of more than 3,000 lives, major U.S. initiatives to combat terrorism, and the initiation of a war that would last more than a decade.
According to PBS.org, there have been several post 9/11 policy changes, which have affected our civil liberties and life as we know it.
The Aviation and Transportation Security Act federalized airport security, which was formerly privatized. This affected our civil liberties by forcing us to go through additional airport security, including new x-ray machines that some experts fear could emit dangerous levels of radiation upon malfunction, among other health risks. There have also been cases of people who were unable to fly because their names were erroneously placed on a national “do not fly” list, as well as women who were harassed about bringing breast milk on the plane under the guise that in violated TSA’s liquid limitation guidelines.
The Enhanced Border Security and Visa Entry Reform Act is a U.S. federal law that requires illegal immigrants in the United States for more than one month to register with U.S. government, and to have papers certifying their registration and status in their possession at all times. Subsequently, Arizona passed Arizona SB 1070, which allowed Arizona law enforcement to try to determine the immigration status of an individual during a traffic stop, detention or arrest or because of suspicion that the individual is an illegal immigrant. This is said to have increased racial profiling, and has therefore affected the right to unreasonable search and seizure of American citizens, whom law enforcement may mistake for illegal.
Department of Homeland Security
The Department of Homeland security was created after 9/11 to focus on preventing terrorist attacks on American soil. It encompasses 22 other federal agencies, and in my opinion, has been one of the most invasive culprits.
In October 2001, the USA Patriot Act was passed. The passing gave law enforcement the ability to conduct searches without warrants, monitor spending habits, eavesdrop, detain and deport, people under the guise of suspected terrorism. This act also allowed the NSA to reportedly spy on millions of Americans and Europeans, eavesdropping on and recording telephone conversations.
While each of these policies may be necessary to protect America from the increasing threat of terrorism, it seems that the laws themselves grant too much leeway to the officials charged to enforce them. Many of these agencies and the policies that they create and enforce provide strong provisions for what an officer thinks may be reasonable, and that is a recipe for disaster.
 PBS.org News Hour http://www.pbs.org/newshour/rundown/911-to-now-ways-we-have-changed/