What is it about graffiti that at once annoys and offends us, but also captivates and astounds us?
I guess it depends on the artist for me. There's a difference between a vandal marking a gang tag everywhere they see fit or daring than an (usually) anonymous street artist. I have felt offended and/or threatened by gang tagging because I'm the innocent bystander who'll be penalized because of where I live. Nobody with a right mind knows or cares about who "Lady Entity" is, or when she "waz ere". Chances are it's in a place which will just get painted over anyway.
However, some tags are pretty astounding - location wise. I've walked/drove under countless bridges in my time, and someone has had the guts to leave a tag on the side of the bridge. You can see where a couple of people have left theirs right up near the edges, but others are right down into the middle. What's also astounding is that someone is willing to risk their life to leave their "mark" somewhere.
You won't catch me up there...
As for what I consider the real art, I could walk around London all day taking pictures of it. More planning was done and considered with such types of art, and portrays a better message or joke to the people who come across it, despite it all being illegal. How can you be threatened by a piece of Banksy or similar artists? People have gone to prison for defacing his work, despite his work being illegal in the first place. He remains as an anonymous urban legend, and when people mention his name, you know immediately who they're talking about.
A couple of my favourite pieces:
Longish:
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