Anti-ad initiative ambushes Madrid shelters

Some rogues in Madrid recently ambushed the bus stops and other public ad spaces with statements protesting advertising saturation. This is apparently an ongoing initiative called PublicAdCampaign. The contributors, who ranged from artists to lawyers to teachers, used their signs to communicate what they wanted to see in public spaces (here's a larger gallery of their work). I like the idea behind the project a lot (and the "Buy me a Coke" sign made me laugh), but I wonder how well the executions actually speak to people.