“The US Supreme Court has upheld a law forcing public libraries to filter out internet pornography in what is being seen as a victory for attempts to protect children from obscene content.”

“The [coalition of libraries, library users and website operators] said the software filters prevented library users from accessing information on subjects they had a legitimate right to know about – eg breast cancer, homosexuality, sexually transmitted diseases, gay rights and family planning.”

“Digital freedom campaigner the Electronic Frontier Foundation released a new study on Monday that suggested that popular filtering programmes blocked tens of thousands of web pages that had no offensive content.” (BBC)
And here’s more on why it’s bad.