fly-post 
verb [with object] British
Put up (advertising posters) in unauthorized places.Mr Bayley's offices in Holgate Road have twice been targeted by fly-posting protesters, firstly last month, and then earlier this month....
- The secret organisation has fly-posted stickers on billboards and bus stops in the city centre with an ‘Up Yours’ message to the town hall blitz on litter louts and other environmental offenders.
- The claims go against some of the opponents to the Coppergate Riverside scheme who recently fly-posted empty shops, claiming 150 were already standing empty.
Derivatives
fly poster
- Has the spirit of Christmas become a bill-board over which commerce pastes a fresh fly poster each year?
- Some councils have gone even further to rid their boroughs of unwanted fly posters.
- Companies putting up fly posters advertising events are finding large "cancelled" notices stuck over them.
Origin
Early 20th century: from on the fly at fly1.