It is art, although we may not like all the murals. Illegal....yes, unless there is a permit received. Philly has some stunning murals on the sides of some buildings where a side is left revealed. It is graffiti, but they are definitely works of art, and here, they add such character to different hoods.
art, yes, NO!
Very much art! I love the murals I've seen. Uninspired tagging, not so much.
It can be both, I think.
Oh dear, cosmic questions without answers. Pass the Soup Can.