Since 2005, the Texas-based graffiti collective Knitta Please has been traveling the globe, handcrafting wooly legwarmers for statues, colorful cozies for fire hydrants and striped hats for outdoor chess pieces. They channel the current knitting trend into international guerrilla art that doubles as street fashion, inspiring other knit graffiti groups in Sweden, Japan and South Africa.

While some call their work vandalism, Knitta says they want to beautify public spaces. Their most impressive feats to date include yarn-bombing the Great Wall of China, tagging the Notre Dame and wrapping half of Seattle’s Monorail. And if you get a chill this winter, they might just knit you a scarf, too.