Google has an ad policy which prohibits criticizing other groups or companies. Recently Oceana tested Google's ad policy by placing AdWords ads critical of Royal Caribbean Cruise Lines. "Washington D.C.-based Oceana believes Royal Caribbean pollutes the oceans by improperly treating the sewage on its ships. It hoped to publicize its complaints by paying to have its ads appear when terms like "cruise vacation" and "cruise ship" were entered into Google's search engine."
(found on Mecury News)

Recently Google has also been slammed for an open policy on pharmaceutical drugs which it was forced to change.

Some people claim censorship with these changes, but Google is still open to advertising if you know how to do it. They still rank George Bush very high for phrases like "unelectable" and "Misserable Failure." Other than AOL, few search engines are trying to censor their fall through search listings.

I personally am making honest feedback about drugs like Paxil and Zoloft more accessible. One of my personal blog pages list well for even the competitive phrase "Paxil side effects."