Nobody can control the inane actions of other people. Personally, I have never understood those that graffiti public restrooms. Sure, once in a while you get something funny as you are taking care of your business, but most of the time, these messages seem to be left by illiterate, very un-funny people. It makes many wonder, isn't this a crime?
You bet it is; especially if you see graffiti in a state-run public restroom. Defacing state property does not have to mean a police car or road sign. People who graffiti a state-run public restroom are also defacing state property and had better hope that hey do not get caught. Such a crime can carry stiff penalties including fines and possibly even a little time in the slammer. This will depend on how egregious the crime was.
With as far as manufacturers have come in making public restrooms a better facility to use, it is a shame that many people will still go out of their way to mess it up. If you see someone committing this crime, don't be afraid to let them know that what they are doing could cost them far more than they bargained for.