k first of all. there are about 3 people on this site any good at graff so dont even waste ur time.
do urself a favour...go to www.bombingscience.com   im on it as much as NS.
graffiti does not promote gangs. graffiti does not promote violence.
real graff heads dont give two fucks weather people like it, hate it, think its art, or think its destruction. they do it for themselves and to represent their crews.
but for the sake of the discussion as drew pointed out...you cant define art or force it into one spectrum like people do when comparing it to graff/vandalism/whatever.
take ur head out of ur ass and think for urself instead of re-gurgitating(sp?) the medias warped message about what graffiti entails, who does it, and what it means.