Updated

Convicted sex offenders are pushing back against North Carolina laws they say deprive them of constitutional rights without increasing protection for children as the laws originally intended.

A Raleigh-based national nonprofit and two anonymous sex offenders sued the state on Monday, saying it's unconstitutional to ban them from churches, colleges and the Legislature's building. The lawsuit also contends the U.S. Constitution forbids changes to the law that add penalties after conviction and sentencing.

The federal suit is part of an effort to prune sex registry laws, which now require more than 800,000 convicts nationwide to register their names, addresses and photographs for up to their lifetimes.

The U.S. Supreme Court next month reviews North Carolina's law banning sex offenders from using social networking sites like Facebook that minors can join.