Had this happen in MPTO to LAX on Copa. Waiting at the gate and these shady characters in uniform came and setup a table, theater line ropes, and had everyone check their carry ons. Open them up ruffle around (in plain view of the entire terminal I might ad) and carry on. None of them spoke a lick of English.

Funny thing was, we were on our way back from our honeymoon and I had been carrying my wife's bag (which was heavier), so I got the priceless look when they opened the bag I had to find nighties and lingerie. HA classic. Was almost worth the invasion of privacy.