An ad on a bus stop just south of 24th Street on Valencia Street has been replaced with a handwritten message.

“Imagine a city that replaces adverts with public arts and ideas,” the poster prompts.

Signed by the Subvertisers International and marked #subvertthecity, the non-ad is part of an international campaign to replace advertising with art and other dissenting messages.

The activists’ aim is to subvert corporate advertising and advance a post-consumerist world.

“Commercial advertising invades our spaces and all forms of media in order to influence our behaviors and mostly privileges big corporate interests,” the activists wrote on their web page. “Commercial advertising has come to dominate our cultures and gives more power to the wealthy, endangering democratic processes.”

The campaign officially kicks off on Wednesday and runs through March 25.