I’d never heard of it until recently, but the international phenomenon of yarnbombing (aka yarnstorming, knit grafitti) seems to have been around for a while. There’s even a book devoted to it. Calling it Yarn Bombing: The Art of Knit and Crochet Grafitti, authors Mandy Moore and Leanne Prain chronicle the history of yarn bombing, offer 20 knit and crochet …