Street art is a bit of a gray area. On one hand, work that comes from true talent, and adds value to the environment and community is great, but on the other there's tagging and just pure vandalism. That's why Banksy is such a controversial figure.
Often, artists' work will get painted over or washed away completely by the government or property owners. In many cases, those same artists will fight back and return to put their work up again — but rarely does this happen multiple times. As documented on Imgur, though, one artist took it to the next level and waged a yearlong battle with the pressure washers that kept coming back to conceal his or her work.