When I read "dumping rubbish and human waste, as well as tree cutting and anti-social behaviour." it reminded me of touring New Zealand where years ago certain backpackers did as such ruining areas resulting in strict new rules and virtually killing off freedom camping there. But hey it was their gap year and they are unlikely to ever return again so couldn't care less about ruining it for anyone else to come. We also witnessed the same in Aussie with irresponsible young backpackers but with less drastic changes taken to combat the problem. Gee, the worst case scenario is to just dig a hole and bury it!
I take all media with a pinch of salt as the true full facts often make for a non story. I find it rather hard to believe that any actual motorhomer's would do as claimed, though guess that there is always the bad minority out there to taint it for the rest.