It just seems so backwards that making a concrete mailbox can get you sued by a jerk that intentionally drove into it. I can understand banning pitfalls and other actual traps, but why passive defensive deterrents? After all, it’s not like a bystander accidentally wandering onto your property is going to be injured by a random bolder you placed between your garden and the street.
(Edit): It seems I had a fundamental misunderstanding of US law. Thanks for indulging my curiosity!
You can be sued for a lot of things the US. Whether they win their case against you is a separate question.
Are you aware of a case where someone attempted to vandalize a reinforced mailbox, were injured in the process, sued, and won? Were the claims related to booby trapping? Feels like these sorts of sensational cases frequently become stories that stray pretty far from reality.
And yes, Canada also has laws against booby traps.