One thing I heard about .... the thieves were not taking the time or making the noise to cut the trailer hitch lock, but instead were simply bringing a wrench and taking the nut off the trailer ball. Then they'd just roll the trailer away from the vehicle & hitch it up to theirs, and off they go in under a few minutes. They'd deal with the lock once they were safely away from the scene.

The "fix" I heard about ... some people were welding the nut to the trailer ball.