The present invention involves a system and method for detecting a graffiti-making act such as the spray of a spray paint can, the writing with a felt-marker pen on a surface, and the scratching with an abrasive instrument on a surface. The system includes one or more sensors adapted to sense the graffiti-making...http://www.google.com/patents/US7064664?utm_source=gb-gplus-sharePatent US7064664 - Graffiti detection system and method of using the same
