Is it possible to vandalize vandalism?

OK, the works of celebrated graffiti artist Banksy probably can't be classified as vandalism anymore, but it's an interesting question that has no doubt been debated ad nauseum by graffiti artists around the world.

But what do you call it when someone vandalizes graffiti?

Whatever you call it, that's what's happened, or is happening, in Bethlehem, where some vandal has obliterated two of Banky's latest pieces of political wall art.

In the waning days of "Santa's Ghetto" someone has whitewashed Banky's silhouette of a soldier questioning a donkey and one of Banksy's signature rats with a slingshot.

Of course no one knows who is behind these dastardly deeds (in this part of the world, they might well be dubbed acts of artistic terrorism), but one prevailing theory is that the images were wiped out by Palestinians who took offense at the images.

Although Banksy pretty clearly meant to satirize Israeli security concerns with the soldier-donkey piece, calling someone a donkey in this part of the world is a pretty serious insult.

And some people (including, apparently, the guy whose house the image was painted on) who saw the soldier-donkey image thought Banksy was suggesting that Palestinians were donkeys.

Same thing goes for Banksy's signature rat with the slingshot - an image well known to Banksy fans.

Some people thought that Banksy was mocking Palestinians and comparing them to rats.

(Another one of Banksy's rats sold for $125,000 at the auction.)

A "Santa's Ghetto" organizer I met shrugged off the assault, but it does underscore some of the classic local-international tensions that sometimes arise when "outsiders" come in and attempt to draw attention to an issue "locals" have been working on their whole lives.

In any case, "Santa's Ghetto" has already succeed in attracting massive international media attention to Bethlehem this Christmas season.

The auction ends on Christmas Eve, but all the wall art will be staying as long as vandals don't obliterate it.

Here's some of the newer additions:

These posters are by Ron English.

Below is a piece by a Miami-born street artist named Swoon who now lives in New York and, like Banksy, keeps her identity under wraps.

Underneath the woman it reads:

When the Bay Bridge fell in the last San Francisco earthquake, we learned that structures resonate to a frequency. A vibration that matches their internal rhythm can bring them down. Massive structures tremble and a fence is only as strong as its point of attachment to its base.