I don't normally appreciate The Man shoving it to people, but you have to give him marks for cleverness on this one.
Glasgow city council has started fighting against bill posters by posting their own bills, with a single word on them ... "Cancelled".
They're getting their message across via the hassle caused to the promoters when customers come to complain, and the lost sales when people ignore the ads, assuming there are no tickets to buy.
Basically, they've made the posters work against the promoters, rather than for them. Sneaky devils.