fly-poster 
noun British
1An advertising poster put up in an unauthorized place.The scrutiny board also wants the council to get tough with businesses that generate litter, cracking down on flyers and fly-posters which end up as litter and stopping commercial refuse piling up in streets....
- The 100-day campaign started on January 12 and has targeted everything from fly-tippers and dirty waterways to graffiti and fly-posters.
- State Street's flowers and trees remain un-vandalised, vertical surfaces aren't covered in fly-posters and graffiti, traffic glides around calmly.
2A person who fly-posts.Firms that use fly-posters to advertise in Manchester have been named and shamed by environmentalists....
- Since then wardens have been handing out fixed fines for littering and fly-posters have been warned they will be taken to court and could be hit with anti-social behaviour orders.
- We are fighting back against the litter louts, the illegal fly-tippers and fly-posters and the vandals who deface the city with graffiti.