Vandalism or Virtuosity?

One of Banksy's many works of graffiti that appeared this month in NYC

Every day this month, New York City has been greeted by a new work of art courtesy of world renowned street artist Banksy.  Each day, the people of the city have woken up to find a new masterpiece by Banksy, in which he has used every corner of New York City as his canvas.  Thousands of New Yorkers have been flocking to see his latest work and to take pictures with his sometimes humorous work.  But, not everyone in New York is thrilled to have Banksy taking a "residency" in their city.

New York City mayor Michael Bloomberg said in a press conference that "...graffiti does ruin people’s property and it’s a sign of decay and loss of control...
I just think there are some places for art and there are some places [not for] art. And you running up to somebody’s property or public property and defacing it is not my definition of art."

First of all, I do understand that rules are rules, and by law, graffiti is illegal, and I understand that.  But, I really think that in this instance, New York should tolerate Banksy's work.  They should be grateful and honored that the most famous street artist in history has chosen their city as his canvas for the month.  Also, I do not think that he is "defacing" the city of New York because frankly, his work is really good.  It's definitely an improvement to any of the dirty, rusted urban structures he utilizes as a canvas.  New York is one of the biggest cities in the world, and is known for its incredible art scene, so it makes even less sense that there would be criticism or opposition to having one of the best artists in the world giving away free work to the city.

Do you think New York and other cities should be more tolerant of graffiti?  Do you think graffiti laws should be changed?