I suspect the average scally, bent on criminality, will not be put off by signs asking him not to.
Thanks for the Map reference. I'll check it out.
The irony of the no access/ more secure thinking is potential witnesses for wrong doing are excluded and alienated by this attitude. The property boom that has put suburbia into rural dwellings means that those country people, who knew what to look for, are no longer the watchful eyes that once picked out strangers and country pubs are no longer the information exchange that processed rural gossip.
Countryside and farm watch schemes would benefit from trusting the 90+% of socially responsible citizens rather than thinking that the super rich and titled are the only honest people around. A scheme using QR codes would probably catch more rural criminals, dumpers of rubbish and dog worriers than all the notices, sensors, hidden cameras etc, if landowners learnt to respect their fellow citizens.