of this program is to ensure passengers and flight crew are protected during air travel and it's not intended to surveil ordinary americans. passengers are selected for surveillance if their foreign travel and other factors raise concerns. including criminal records, curious financial transactions, e-mail or phone numbers that could be tied to terrorism. we recently talked to tsa chief david pikosky about the air marshals. >> we keep their presence covert because we don't want our adversaries to know they're on particular flights. >> reporter: but passengers aren't told if they're on the "quiet skies" list or what happens to the information collected about them. some federal air marshals complain the program is a waste of money. the unions saying the american public would be better served if these marshals were instead assigned to airport screening and check-in chaiareas so activ shooter events can be prevented. >> it should go without saying government agents shouldn't be monitoring travelers without a good reason for doing so.