Simple tagging is the equivalent of a dog cocking it's leg at a lamp post and mindless vandalism.
It's not cool, it's just damages peoples property, looks a mess and upsets people.
I think graffiti is ok and sometimes is very talented, but only in the right place.
People who spray tags on signs in memorial gardens, on historic buildings, houses or businesses. . . .well get to feck I say.
I do enjoy seeing real graffiti art in an area which is suitable as in good cases it can improve or add to the local enviroment.
There is a tagger in Manchester called FYM and I would love him to be shot at dawn.