If you are an American, you can thank these two senators (John Mccain and Fritz Hollings) for censoring a large portion of the internet and preventing people from gaining knowledge and learning.
>"Schools and libraries subject to CIPA may not receive the discounts offered by the E-rate program unless they certify that they have an Internet safety policy that includes technology protection measures. The protection measures must block or filter Internet access to pictures that are: (a) obscene; (b) child pornography; or (c) harmful to minors (for computers that are accessed by minors). Before adopting this Internet safety policy, schools and libraries must provide reasonable notice and hold at least one public hearing or meeting to address the proposal."
It is because of them that filtering software such as IBoss exists and why schools have google integrated within their computers to force students to use their services and to use a filtered search.