Un huh. I've been using a Hollywood receiver hitch for something like four years and normally leave it on all the time. Our theives are mostly opportunistic, though. Not too many are carrying around a 3/4" socket on a 1/2" drive ratchet. I've considered getting a longer bolt and adding a lock nut to the threaded end. Then they would have to carry two wrenches. I do often take it off before longish highway trips. There's always a chance some state police officer is having a bad day and decide my license plate is obscured.
I love the rack, by the way. I can't imagine a quicker and easier way to get one bike off the rack and on the road. Two bikes would be much more than twice the effort, if that affects your decision.
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Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.