Campsite encroachers. I have had to move bikes, chairs, and picnic tables because they were so close to my trailer I didn't have clear access to empty my tanks. Kids are kids and I get they drop their bikes where they jump off of them but...adults moving picnic tables so close to another trailer is beyond inconsiderate. Same with fire rings being close to other sites...granted, that is the fault of the CG but some rings get moved by the campers when they are not supposed to be moved. Basic inconsideration of others is the big issue. For the most part, the good experiences out number the bad.