About stepping in Legos, check this cartoon from artist Caio Slikta:
http://img814.imageshack.us/img814/6595/scan0036.png

"Pixador" is the one who just write it´s own name (or its gang´s name) around the city, and the target is the difficult of the location (high buildings or locations under police watch). No respect for the owner of the wall, a statue or historical location. In my opinion, just a bunch of ignorants, jealous of others success.