How common are parks with "cheater" 50amp service?

I disagree wholeheartedly with the signage idea. It is impossible to sign every possibility of misuse of the park. There is another thread running where someone's kids spraypainted trees and picnic tables. Is a sign needed for that as well? If you want to use the park facilities for anything other than what they were intended for, ASK. (And be willing to accept the answer)