You really must be fucking retarded...
Limiting graffiti should never be an option, the thrill is hitting a public spot thats great in view/etc
Oh, and btw, Ive never seen a tag thats taken a few hours to clean. I was able to clean a 4' x 4' bomb on a storage unit with a can of fucking goof off and paper towels in about 10 min. I did this multiple times. If the piece was too big, simply painted over it. Along with that, it generally comes off glass quite simply. Fuck off.
Smoking weed doesnt harm others? Well, for me it causes seizures, others it triggers medical problems such as epilepsy, and unless you grow your own, where the fuck do you think weed comes from? mom and pops in a forest? Oh wait, that is true in kentucky, but they also have landmines, and fish hooks hanging for Police who raid the place. Fuck off.