Google filter blocks innocuous sites
"A new report prepared by Harvard University's Berkman Center says that Google's filtered search technology incorrectly blocks tens of thousands of innocuous Web pages, including ones created by Apple Computer, IBM, the White House, the Library of Congress and the Washington Post."
"The errors arise because of the way Google designed its SafeSearch feature, which can be enabled or disabled through a preferences page. Instead of requiring human approval before Web pages are labeled as adult, Google uses a proprietary algorithm that automatically analyzes the pages and makes an educated guess." (from Cnet)