“We have made every reasonable attempt to insure that our web pages do not contain links to any questionable material or anything that can be deemed in violation of the district’s Acceptable Use Policy. Linked sites are not under the control of the district. Therefore, the district is not responsible for the contents of any linked site, or any link contained in a linked site. The inclusion of any link in a web page hosted on the district’s server does not imply endorsement of the site by the district.”