The American Civil Liberties Union is threatening to sue Tennessee public school officials if they do not stop restricting students’ access to lesbian, gay, bisexual and transgender Web sites on school computers.

Tennessee schools are connected to a statewide computer network that uses filtering software that groups Web sites into different categories, eSchoolNews.com reports. Local school officials have the ability to block or unblock those categories.

In a letter dated April 15, the ACLU said as many as 80 percent of public school districts in the state might be blocking access to non-sexual sites that offer educational and political information about issues like gay marriage.

The letter alleges the software blocks all sites designed as such by default. Federal and state laws only require schools to use filtering software to restrict obscene or harmful information.

The ACLU demands the schools have a plan to restore access to sites designated as lesbian, gay, bisexual or transgender for the 2009-10 academic year by April 29, eSchoolNews.com reports.

The company that administers the filtering software issued a statement saying said it is up to its clients to determine what material to filter, and representatives from the Metro Nashville Public Schools and Knox County Schools said they were reviewing their policies in response to the ACLU's complaint.

Click here to read the full eSchoolNews.com report.