Happened to me last year - on a flight, stayed over at an airport motel. Next day Amex sent me an email saying they’d declined a charge. It was for R5000 from India; a specialty grocery store. Seems the guy who ran my Amex card is Indian and out of the three motels on my trip he was the only one who could have done it. R5000 is equiv. to $75.
Couple of years ago Amex cancelled hubby’s card twice within a 6 month period for charges out of state that weren’t his. He had never left home.