throw some tiny part the tsa considers a firearm into your luggage and it'll never get lost again. this also allows you to use your own locks instead of the tsa mandated ones which anyone can make a key for. every baggage handler knows what the red tag means, who's gonna target the bag that's guaranteed to have the atf crawling up their ass?
edit: i'm pretty sure they also won't send it on those courier services like in the twitter post cause most of the time i have to show id at the airline's desk to pick it up