Thought I would pass on an experience I had the other day with a hitch pin lock, the kind that replaces the regular 5/8" hitch pin that goes through the receiver and hitch.
We needed to change to a hitch with lower offset but couldn't find the key to the lock. One guy suggested getting a reciprocating saw and cutting it off, but I figured it was hardened steel. So, I got my hammer out. 3 or 4 heavy blows later the pin broke right off at the lock. Took about 30 seconds.
As someone said, locks only stop the casual thieves.