Serious Motivations Behind Graffiti: Artistic Expression, Recognition, or Impulsive Behavior?

I do graffiti because I love it. Putting my tags everywhere gives me a thrill, kind of like what s*rial k*llers might feel—though, don't worry, I'm not into that stuff. When I go back to where I tagged, I get that rush all over again.

I'm curious, though: does anyone else feel this way about their art? If you're into graffiti, do you do it just for the art? And for those who aren't into it, what do you think—art or just vandalism?