[Volpe]

By that definition, tagging an (original) poem is art?

[pippy]

Yes.

The definition of art is more a philosophical question that varies from person to person, so getting consensus on defining what Banksy is is bound to ask the question. Perhaps that's one of his objectives.

[klenwell]

For one influential academic answer to this question, see http://en.wikipedia.org/wiki/The_Anxiety_of_Influence