I was on a friend's boat when he fell victim to one of these ignorant and empowered people.
The proper way to tie a boat to a piling is with a pile hitch (not 2 half hitches, a clove hitch, and a bowline is too fragile by losing half of the rope's rated strength).
Windy day. We came back to find his boat moved and against another boat. (edit back to my original post, which was changed by the moderator) "Capt. BH" had improperly tied up the boat after he moved it. Both spring lines were tossed back in the boat and the stern line had let go. The bow-line wasn't even a knot, just kind of barely holding on.
So please don't move someone else's boat. It might be mine, and I will make a thread about you.