The FBI looked at everything - in totality - and said they could fly. All the pieces added up to "not terrrorists."
This seems to be a distinctly miority position in here, but I think tht AirTran crewed up big time on this one and deserves every bit of teh legal reaming it is about to get.
Okay, a passenger overhears something suspicious. The FBI is called in, does some checking and, finding no danger, recommends that the family be free to travel on. But never underestimate the power of airlines to be heartless bastards. They not only refused the investigating officers' recommendation, but refused to let the family fly again FOREVER. I understand that AirTran has had to backpedal on this last bit since the incident.