“It’s positive to see others reacting with indignation against our elite,” said Djan Ivson Silva, 27, a pichação gang leader. “We take our risks to remind society that this city is a visual aggression to begin with, and hostile to anyone who is not rich.”

Retaining that edge is essential for self-described subversives who draw their underground legitimacy in part from their clashes with the mainstream art world.

Even as São Paulo’s other forms of graffiti acquire some respectability as street art, shown in galleries here and abroad, pichação (pronounced pee-shah-SAO) remains defiantly outside such conventions, inviting visceral reactions from those weary of its relentless scrawl across the cityscape.

“They make buildings look grotesque and walls look disgusting,” said Telma Sabino, 45, a secretary, echoing the anti-pichação sentiment of many other Paulistanos, as residents of this city are called.

Pichação does, however, fascinate scholars of urban culture, who have studied it since it emerged here in the 1980s. They say that it differs remarkably from other forms of urban graffiti around the world inspired by New York’s colorful lettering from the 1970s.

Often applying black paint with rollers instead of using costlier spray paint, the graffitists were influenced by the record sleeves of foreign bands like Iron Maiden and AC/DC, themselves influenced by gothic lettering and Viking runes, said François Chastanet, a French scholar and author of a book on pichação.