If you haven't heard, the Bristol street artist Banksy is in New York City this month putting on an outdoor art show of sorts titled "Better Out Than In". Local taggers and graffiti artist seeking attention and the need to protect their own "turf" have been going over Banksy's work about as soon as it's put up.
It's frustrating to know that Banksy's work will not last long enough for me to ever travel to NYC and see it in person. If it's not the attention whore taggers writing over it, it's the city itself washing it away. But, that's the understanding that every street artist has. They have a detachment from their own work because they know it will not last forever. It's not meant to. Even if it survives the defacers and pressure washers, it will fade away due the rain, sun, and wind. What makes so many pieces special, is that it is there for only a brief moment in time.
Still, there is a bigger enemy to Banksy's art. It's those who take the pieces from the streets to sell and profit for themselves. Some people label him a "sell-out" because of his commercial success, but if he's getting paid for work he's done and someone wants to give him $1 million for it, then good for him. If someone who had nothing to do with the work gets paid even $1 for it, well, I don't think theres even an argument to be made why that's not completely stupid. (On a related note, some douches were guarding the beaver on Bradford St and charging people to see it.)
All the people who feel the need to paint their name over his work to in some way teach him a lesson or for their own recognition, are doing Banksy a favor. If it's defaced then there is no value. The piece actually is protected in that way. For that reason I'll probably never see a NYC Banksy in person, but I would rather look at photos of them than know some jackass lifted it from the streets and sold it to some other jackass art collector.