http://www.ucalgary.ca/uofc/students/VOX/Features/graffiti.htm
This story is written by a friend of mine, a long, long time ago (1996). It's an interesting read, though, I recommend taking some time to read it.
Had to adblock that dumb background. Reading now...
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Nice read. I do like most of the pieces that are tossed up around Philly, and tags have always bothered me.