When São Paulo introduced its Clean City Law (Lei Cidade Limpa) a decade ago, over 15,000 marketing billboards were taken down. An additional 300,000 ostentatious business signs, hanging over streets or painted in large letters on facades, were also subject to a hefty fine if they were not removed promptly. Bus, taxi, and poster advertisements had to go as well. Even handing out pamphlets on the street was prohibited. While this legislation helped clean up the largest city in Brazil, it also revealed surprises hiding behind ad-covered urban signs and surfaces.