Hi Frank,
I've no affiliation with the law and I find what you have informed us about VERY interesting, to say the least.
Not having had a need to yet, but I am sure that I will encounter such confrontation eventually, on what is known as public open space and crown land vested in the interest of the local council. Parks vacant land and the such.
I think what you have mentioned is so true and I am going to see if I can apply such a democratic right to our use of such land, in the event that I have to, for retrieving buried targets with a metal detector, here in the capital city of Western Australia.
I believe their are some park gardeners, rangers and private security guards over here, who seem to sometimes over state their importance over our rights on how we should use a PUBLICLY owned park or reserve. Fancy being NOT allowed to use a public park to retrieve a small lost metal object with a minimum of fuss or "damage" as they might want to call it, from a lawn that we, as the public in a "democracy" are supposed to have the use off. So long as you are not creating a public nuisance or endanger life, what could be wrong with it? I think it's mainly based on the accusers stupidity, ignorance, arrogance, mis information , envy and the necessity to again "paint us all with the same tar brash" as being the MAIN problem.
As many of us are aware, we, as people who make up the public and who have chosen to indulge in a hobby such as metal detecting, that gets many of us in and around a public reserve to search with metal detectors for lost metal objects that MIGHT happen to be there, are actually the least of the problem folk they should be concerned with.
Provided we have used discretion in how we leave the state of the ground of such public places(covering any holes and removing trash that is recovered as if is left there it can possibly become a public liability issue). If it can be proven one had left a hole, loose dirt or trash to trip over or for trash dug up that might get caught in a lawn mower and flung at somebody or damage the machinery, then the onus of responsibility may rest with an authority or it's servants who would some how feel it should prevent any of these occurrences. Hence , giving us the chits about it. It may be pedantic and over zealous BUT where is the "line" drawn?
On the other hand, I also feel they should in actual fact be THANKING us for being there. Rewarding or even paying us to be there. It's probably the only way, in some cases, they will get decent law abiding folk to come to there phuking parks and use them at times to the exclusion to the trouble makers how might be there when these people who call themselves the "authorities" might not. I'm not suggesting we are should or may be dooing their job for them BUT we are not to be considered a problem like Mike has described how he might have been to that foolish "lady" who had the balls to creep up on him......
Anyhow, thank you very much for the info.
I think it's going to be very useful even to me here on the Aussie West Coast.

David E Di Prospero