On the catching vandals thing, many years ago while working as a pizza delivery guy one of my regulars was in a less than desirable area. Across the road was the original home prior to subdivision. Big white picket fence running down two streets. Invariably you would see ugly tags on it and then by the next week the owner had painted over them. This was an ongoing battle.
One night I was delivering pizza and saw a kid start to tag the fence as I was about to run over he suddenly slammed into the fence a couple times, then a big cloud of paint. The owner had grabbed him through the fence and then sprayed the contents if the can all over him. Not bad for an 80 year old.