Libraries began using Internet filters in the late 1990's due to community pressure and the Children's Internet Protection Act (CIPA). CIPA is a federal law that requires all computers in a public library to be filtered if that library accepts any federal funds for computers that access the Internet or the costs associated with the connection to the Internet. It took effect on July 1, 2004.
The use of filters in libraries has increased steadily. Some municipalities require libraries to use filters. Some libraries choose to use filters -- at least provide patrons with the option. And, some librarians argue that filters have no place in a library.