In reply to Jim 1003:
It can be enforcable if the owners are prepared to take you to court over non-payment. However, it would be expensive for them with a risk of losing. Same for the person who parked. Historically, people usually get away with it, as it's just not worth their time or money. People parking in NT car parks without paying have usually got a nice note requesting they pay next time. I am not condoning this, just stating what people I know have experienced.
As for Walna Scar, it would be up to the people who own the land, Rydal Estate as I understand, to prosecute privately, so a mass, or even an individual non-payment protest might not get a prosecution for the expense of it. I really don't know, so don't take what I say as law.
Hopefully the lovely Walna Scar car park will remain free. All that needs to happen is for physical restrictions to be put in place to stop off-roaders going further than the car park area. I'm sure the outdoor community would be prepared to contribute to that instead of car park fees. I certainly would contribute.
I need to add that anyone not paying in a council or government type car park will be open to full prosecution under national law, i.e. not privately run, but backed by the Crown. This includes local councils and the National Park car parks. That one you will definitely lose.
Post edited at 21:54