I use spraypaint to prime and paint models. Some people use spraypaint to touch up their cars and houses, or paint furniture.I think the sale of spray paint should be regulated as well as prohibited to minors. What uses do most people need it for anyway? Though I'm sure the brain-dead degenerates will find some other way to tag property, it may help with the ease in which they do it.
I'm also bitter because someone tagged the buildings at the end of my street (which had just been cleaned from a previous tagging). I swear if I ever catch them, they'll be coughing up spray paint for the rest of the night.
And really, the only real problem with graffiti in general is simple tagging, just scrawling a name without providing any actual art. A much better solution would be to work around the whole graffiti culture, promoting the art and doing away with random tagging. Set up community art opportunities, places where graffiti artists can paint on walls to actually make the city more beautiful. Maybe even have graffiti workshops to build skills in artists so we can have nicer graffiti, encouraging people lower down to do away with random vandalistic tagging and aspire to great art. Graffiti could certainly make the city more beautiful if we didn't generalize all of it as "mindless vandalism."
btw, I actually quite like that sign on the Millwood bridge. I could imagine coming down to work in the morning, seeing that there, and having a great day because of it.