It's taggers vs. artists in San Francisco's graffiti war

By Richard Ehrlich, for CNNUpdated 3rd September 2014
Artist Carlos Daniel Perez-Boza works on an authorized mural in the Mission District.
Artist Carlos Daniel Perez-Boza works on an authorized mural in the Mission District.
Photo copyright by Richard S. Ehrlich
Mats Stromberg's "Giant Selfie" mural has been all but obliterated by tags.
Mats Stromberg's "Giant Selfie" mural has been all but obliterated by tags.
Photo copyright by Kenshin Tomoshima
The brick walls of San Francisco's Chinatown are an ideal surface for muralists.
The brick walls of San Francisco's Chinatown are an ideal surface for muralists.
Photo copyright by Richard S. Ehrlich
Taggers spray-paint initials, names, words, acronyms and other lettering across virtually any surface they choose.
Taggers spray-paint initials, names, words, acronyms and other lettering across virtually any surface they choose.
: Photo copyright by Richard S. Ehrlich