“Within hours of the terror attacks on Sept. 11 [2001], law enforcement officials say, F.B.I. agents intercepted telephone calls in which suspected associates of Al Qaeda in the United States were overheard celebrating the attacks on the World Trade Center and the Pentagon. In the following days, the officials said, agents swept in and arrested them and have been holding them since, some as material witnesses, based on the information picked up in the phone calls.”
– Neil A. Lewis and David Johnston, “Jubilant Calls on Sept. 11 Led to F.B.I. Arrests,” The New York Times, Oct. 28, 2001