by Cliffy73
They remain on the buildings until some future turn (it could be several rounds later) when that player decides to take a worker action at another building. But also if the building's ownership changes (because the owner sells it to the town or it's a public building that someone buys) the player takes back their worker disc.This is one way to force someone off one of your buildings, but it means you don't own the building anymore (and you only get half its value from the bank), so it's tough to bring yourself to do it.