What happens when a faux street artist meets a real one?

I have to hand it to Shepard Fairey - the content of his work may be banal, but the marketing of that work, and the imposition of it on the city by the ICA and its comrades-in-arms, has proved to be the cultural gift that keeps on giving. Indeed, I think as unconscious self-critique it's almost unparalleled; few cultural events have revealed the hypocrisy of the presumptively hip in such a harsh, unsparing light. Above is what happened to one of Fairey's murals installed in Providence (hat tip to Greg Cook). Could the unknown street artist in question have made a more succinct comment? What's most wonderful about the added graffiti is that it doesn't really spoil the design of the (plagiarized) original, but instead frames it in a richer, more truthful cultural context. I'd say we have an early front runner for next year's Foster Prize. That is if the ICA has any sense of humor.