When he refused, the FBI agents “kept him on the list in order to pressure and coerce Mr. Sajjad to sacrifice his constitutionally-protected rights,” according to an amended lawsuit filed Tuesday in federal court in New York.

The lawsuit, filed on behalf of Sajjad and three other men, accuses the United States of violating their rights by placing or keeping them on the no-fly list after they declined to spy on local Muslim communities in New York, New Jersey and Nebraska.

“The no-fly list is supposed to be about ensuring aviation safety, but the FBI is using it to force innocent people to become informants,” said Ramzi Kassem, associate professor of law at the City University of New York. “The practice borders on extortion.”