Having been a former range manager, I know just what you mean.....All of our targets were ballistic steel...No steel penetrating ammo was allowed..No Green Tip..etc.....signs and warnings posted everywhere...in the club rules documentation...No .50BMG on ANY steel..etc...They still shot it up anyway...Unless you have someone to monitor every shooter for every moment its going to happen..Either out of stupidity or lack of respect, they going to shoot holes in the steel and anything else that is downrange.
We had a junker car in one of the bays we used for training and matches.....Big sign posted that the bay was 'off limits' to all members...Car had sign painted on the doors and trunk..DO NOT SHOOT...We took it out within a month as it was so full of bullet holes it was dangerous to use..no glass left either...