ron, just curious: who is "they" and why would this "they" not allow someone on the beach? Is there expected to be such dangerous or damaged beach, that .... no one's allowed on the beach?
We had a situation here where erosion got so bad during some storms in 1997-98, that one beach put up "closed" signs at the stair-way sidewalks that led down to the beach. Waves ... in some spots ... crashed un-inhibited up against shear cliffs, since the beach had eroded away in spot to erase the wave's normal stopping points. However, most of the other portions of the beach still had beach sand left on them (albeit eroded there too). As I looked down from the city streets above, seeing this yellow ticker tape across the stairway leading down, I noticed people down on the beach, none-the-less Dog walkers, people gathering driftwood, or ... for whatever reasons. They had simply chosen other paths down, rather than the ones I was looking at. And from there, simply walked north or south.
It occurred to me then, that the only reason the city put up the yellow ticker tape at the main-walkthrough points (although they can't cover every conceivable walk-in point for a 2-mile long beach!) was to "cover their butts". That way, if someone got clobbered by a wave and washed out to the sea, no one can sue the city and claim "you should have closed the beach" or whatever. But the reality was, people were still on the beach. No one was "kicking them out". But sure, if I'd gone to city hall and asked "can I go down on the beach?", no doubt, I would have found someone to tell me "no".
So what is the situation with the beach in this post? Were you saying that because they attempt to "close the beach"? Or are you referring to a beach that "doesn't allow detecting" to begin with? Or what?