As far as street pranks go, this one is pretty sophisticated. And funny. Here's the "legal to pee" prank that hit Nottingham, UK:
The signs, which were put up by pranksters in and around Nottingham, are designed to look official.
They feature a toilet sign and include the words: "Public Urination Permitted After 7.30pm".
Nottingham City Council is now urging the public to ignore the notices as it sets about removing them. [...]
The prank also featured a laminated note, headed with the logo of Nottingham City Council, which said the scheme was aimed at reducing the mess faced by residents outside their homes.