Most organized cavers are aware of the sensitive nature of caves and take measures to minimize their impact. Unfortunately, not all cave visitors are conscientious. Some maliciously break formations or paint slogans and obscenities on the cave walls. Others leave candy wrappers, beer cans, carbide waste, and other debris in the cave. Even careful, well-trained cavers eventually have an impact on heavily visited caves.

Graffiti is a very common problem. Some people might feel the sign at right is justified to help cavers find the way out from a confusing junction room. But eventually, someone comes along and paints such signs at ALL the room exits, leaving the correct one ineffective. In the long run, these "helpful" signs just encourage others to vandalize the cave. When necessary, experienced cavers use flagging tape to mark their route -- and remove it on their way out.

The thoughtless actions of cave vandals sometimes prove to be their own undoing. It's not unusual for a vandal to paint his own name on the wall, sign a cave register, or otherwise leave evidence that helps track him down. In 1993, the first successful prosecution of damage to a non-commercial cave under the Indiana Cave Protection Act occurred when trespassers entered a cave in Washington County and wrote their names and references to their high school.