Ways not to lock your bike

Actually I don't think there is a law that signs can't lie, at least there isn't in England. Next door to where I work there is a roman wall with a door way in it which basically means it's a right of way. The hotel who's grounds you have to walk through don't like this so they've put up "this is not a right of way, and may be closed" signs. This is a lie, but as long as they don't lock the gates at either end of the walk way (at least if they don't do it for long enough for a court order) then it doesn't matter and it probably lessons the traffic (non motorised) through their grounds.

Im thinking in particular about signs that say 'bikes will be removed'. If your bike is illegally taken by the business owner you could nail them for it, so Im guessing that it isn't illegal. I am not a lawyer, though.