AIRBNB squatter

Squatting has become a large problem recently, but they've been doing it for years. About ten years ago a good friend kicked his son out (drug problems), so the son does a change of address and moves into Mom and Dad's rent house. Because he had a bogus rental agreement with forged signatures on it the cops could do nothing. They told him it was a civil matter and he had to take his son to civil court. It drug on for over a year costing my friend 1,000's of dollars. When the courts FINALLY put the kid on the street, the house was a total wreck on the inside that Mom and Dad had to fix to make the place livable again. They spent even more money to fix what the kid and his friends damaged. Unfortunately the kid over dosed before they could get him clean and sober.