Yarn bombing or yarnbombing is a type of graffiti or street art that employs colorful displays of knitted or crocheted cloth rather than paint or chalk. The practice is believed to have originated in the U.S. with Texas knitters trying to find a creative way to use their leftover and unfinished knitting projects, but has since spread worldwide. While other forms of graffiti may be expressive, decorative, territorial, socio-political commentary, advertising or vandalism, yarn bombing is almost exclusively about beautification and creativity.
Every time I have enough leftover yarn to yarn bomb something, my conscience gets the better of me and I knit squares to donate for blankets for those in need.