In recent years the allure of street artists and their increasing fame has generated heavy prices on the auction block. There’s an inherent difficulty here because 1) the pieces are site specific and 2) taking and selling property is stealing. British artist Banksy has taken steps to solve this problem. Establishing Pest Control as an authenticating agency, Banksy hopes to both dissuade people from destroying property for profit and make sure that his own works are not sold. This authentication system works to keep the intent of street art as honest as possible. (via GQ).