I'm not so sure. Making a false police report is illegal. I don't know what they told the police that resulted in the OP's detention, but calling the police because they were made suspicious by the OP engaging in the clearly legal and constitutionally-protected act of photography clearly crosses a line. First, as has been pointed out time and time again, photography in an airport is legal, photography of a checkpoint is legal, and photography of TSOs is legal. Using someone's taking photographs and, particularly, outside the sterile area as grounds for interrogation and detention is, almost certainly, unconstitutional and illegal. Second, given the number of TSOs who have posted here about how they don't "want" to be photographed, it is at least reasonable to infer that, with respect to the IAH TSOs, the whole escalation was retaliatory. That, too, is illegal.