Would you have bought your house if it had been next to a trailer park? Didn't think so. So, why would you have the trailer park come to your house and tolerate it?
The main issue is the risk of your campers going non-linear, especially due to drugs. May be the nicest people when sober too. The fact that they live out of their car makes them high risk candidates for trouble.
Call me cold-hearted, but my family's safety is priority #1.
PS: Where do they take craps?
G