Originally Posted by
stifle
Eh? TSA doesn't run customs checkpoints, nor are there WTMDs at the customs checkpoint.
After you exit Customs you must pass through a TSA checkpoint to enter the concourse. At JFK, you have an option to exit the terminal or return to the concourse. At other airports, like ATL and CVG, you must go through a TSA checkpoint to even leave the airport.
(noted that some folks have cowed the airport/TSA into an individual exception at CVG and possibly ATL, but it is a rare exception rather than the rule.)