Why don't Google remove Michelle Obama image?

What possible reason can Google have for not removing this crudely manipulated picture of Michelle Obama from their images search page.
They are aware it is there but decline to act.
It is childishly racist and should be taken down.
"It's offensive to many people, but that alone is not a reason to remove it from our search index," Google Inc. spokesman Scott Rubin said. "We have, in general, a bias toward free speech."
Free speech, pah! The company says nothing is removed unless the content is illegal or violates the company's webmaster guidelines.
Surely it's time they had another look at those 'webmaster guidelines'.