Bill Posters Will Be Prosecuted.
So read the sign which appeared all over the London underground, at least when I frequented it in the early 1980s. The mischief aimed at, of course, were the unauthorized notices, advertisements and the like mosaicking the walls everywhere. Amusingly, someone had scrawled across several of these warnings: ‘Bill Posters is innocent!’
Unless you have lawful reason, it is a criminal offence to enter or be upon any land, without the permission of the lawful occupier, owner or person in charge of the land.2