From:
https://en.wikipedia.org/wiki/No_Fly_List#Notable_cases
The No Fly List is a list created and maintained by the United States federal government's Terrorist Screening Center (TSC) of people who are prohibited from boarding commercial aircraft for travel
within, into, or out of the United States.
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Walter F. Murphy, McCormick Professor of Jurisprudence at Princeton, reported that the following exchange took place at Newark on 1 March 2007, where he was denied a boarding pass "because I [Murphy] was on the Terrorist Watch list." The airline employee asked, "Have you been in any peace marches? We ban a lot of people from flying because of that." Replied Murphy, "I explained that I had not so marched but had, in September 2006, given a lecture at Princeton, televised and put on the web, highly critical of George Bush for his many violations of the constitution." To which the airline employee responded, "That'll do it."
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In October 2008, the Washington Post reported that Maryland State Police classified 53 nonviolent political activists as terrorists, and entered their names and personal information into state and federal databases, with labels indicating that they were terror suspects. The protest groups were also entered as terrorist organizations. During a hearing, it was revealed that these individuals and organizations had been placed in the databases because of a surveillance operation that targeted opponents of the death penalty and the Iraq War.
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Abe Mashal, a 31-year-old Muslim and United States Marine Veteran, found himself on the No Fly List in April 2010 while attempting to board a plane out of Midway Airport. He was questioned by the TSA, FBI and Chicago Police at the airport and was told they had no clue why he was on the No Fly List. Once he arrived at home that day two other FBI agents came to his home and used a Do Not Fly question-and-answer sheet to question him. They informed him they had no idea why he was on the No Fly List. In June 2010 those same two FBI agents summoned Mashal to a local hotel and invited him to a private room. They told him that he was in no trouble and the reason he ended up on the No Fly List was because of possibly sending emails to an American imam they may have been monitoring. They then informed him that if he would go undercover at various local mosques, they could get him off the No Fly List immediately and he would be compensated for such actions. Mashal refused to answer any additional questions without a lawyer present and was told to leave the hotel. Mashal then contacted the ACLU and is now being represented in a class-action lawsuit filed against the TSA, FBI and DHS concerning the legality of the No Fly List and how people end up on it. Mashal feels as if he was blackmailed into becoming an informant by being placed on the No Fly List. Mashal has since appeared on ABC, NBC, PBS and Al Jazeera concerning his inclusion on the No Fly List. He has also written a book about his experience titled "No Spy No Fly."