Actually, by November 2001, the Times was reporting that somewhere between 500 and 1000 miscellaneous Muslim males, of varying immigration statuses, had been picked and held, largely incommunicado, mostly without charges or lawyers.
Then as now, this wasn't law enforcement; it was a panic attack. Like the French, few in the U.S. objected to this blanket racial and religious profiling. None of those swept up in this dragnet were ever charged with terrorism. Perhaps the French can undercover some real perps? That doesn't seem to be what dragnets do.