My cousin is the county highway engineer here and we have a road sign with 420s on it that is always stolen. He said they tried using bolts that required a special tool to remove and people just ripped the entire pole out of the ground. They went back to regular bolts so they just have to put up a new sign every few weeks.
We have joked about hooking up a fence charger to it, which I think would be hilarious.
That brought up a great memory and made me smile. I was born and raised in Roselawn, In.. Back in the 1950's we had a stop sign in the middle of the street where the street met route 10. A couple of misfit kids thought it was fun to knock the sign down with their old car.
After replacing the sign post 3 or 4 times the Highway dept. set an 8 foot or so of railroad rail in as a signpost probably 3 foot deep.
A couple of days later the rail was leaning just a little and there was car grill pieces and antifreeze in front of it. There was also a car parked in front of an old house with a whole lot of front end damage. (later moved to the junk yard). I'll bet the highway workers chuckled every time they passed the sign!