Well How would you feel if you owned a building or property and some kids or adults came by and Graffitied on it? It would cost you money to remove and it would just be a pain in the ass. On the other hand if you were doing it to a train or just public property or just something along those lines I don't have a problem with that. Its just some what disrespectful and I think people should get arrested for it when they spray paint or graffiti a building that actually has value and is currently in use and not broken down or just abandoned.
holy shit bro. Good luck with your art, I support anything thats abstract. But yeah don't do it on private property unless its like Monsanto, fuck them up.