Neither graffiti nor trash is appropriate in a cave. Additionally, drinking in a cave further endangers both the cave and the partying visitors. Animals living in caves need an extra measure of caution and respect. Bats, in particular, require your care. Waking up a hibernating bat uses up its fat reserves and can cause starvation before its prey species return in the spring.
Maternity colonies are similarly vulnerable as the young can be dropped.
The Park Service, cave owners, the NSS, and others organize cave cleanups. Often these trips are the only way to see beautiful passages that are otherwise closed to visitation. The formation could not be completely cleaned because some mud was crystallized into the formation. Still, it was well worth the effort. This stalagmite was broken, but fortunately the pieces were left behind.