Blimey - so this one pops up again. Since Rattle's original 06 post we have of course been introduced to the new anti-terror laws.
So - imagine that you land without permission, get asked to leave and refuse. The landowner calls the police. They arrive to be greeted by your bolshie self quoting the ANO, no police authority, no law of trespass etc.
Any police officer would take that as an invitation to detain you under the anti-terror legislation. That's why they are telling hotels to provide details of helicopter movements - because they can.
And now that Lord West has disappeared with the old govt, let's hope we get some sense into the legislation. But I doubt it.