Yep, there needs to be more of that I'm afraid.Parking tickets soon sort that out for the majority who think paying doesn’t apply to them.
On the south coast where Dad lived and I was a frequent visitor, early one morning I saw a large MH with toys chairs and crap left heaped up outside it, which had clearly been parked overnight right in the middle of a seafront car park with clear signage saying that overnight stops were not allowed. Less than 1/2 a mile away there's a nice wide quiet lay-by. It has no sea view but there are no restrictions and there was often a van/mh or two tucked up there peacefully overnight. Now, thanks to people like the MH illegally parked and others parking illegally and inconsiderately, with an increasing local hostility to MHs in general as a result, that car park and a number of others has height barriers. I may think 'yay, my VW will fit under the barriers' but NO! The restrictions now state that NO campers or motorhomes are allowed to park on the affected car parks AT ANY TIME, and the peaceful lay-by round the corner also has 'no overnight stops' signage up. Just one example of how selfish and entitled use of parking/overnight sleeping/camping increasingly restricts even regular day to day visiting of nice spots.