Sao Paulo goes completely ad-free with Clean City Law Favorite 

Mayor Gilberto Kassab passed a Clean City Law that banned all public advertising in Sao Paulo, one of the world's most populous cities. The mayor gained the support of the city's elites in pressing the law as an anti-pollution measure targeting "visual pollution". The city was quickly stripped of its ubiquitous billboards, signs, graffiti and other public ads. The measure has garnered the overwhelming support of the city's residents.

In 2012, Mayor Kassab relaxed the Clean City Law to allow designated spaces for graffiti and street art. In response, multi-national corporation General Electric capitalized on the exemption by commissioning a series of murals on a number of buildings in downtown Sao Paulo. The 120-foot tall murals aren't branded messages, though a GE logo does appear on the building facades.