WASHINGTON, United States (AFP) — The US Supreme Court unanimously struck down Monday a North Carolina law that barred registered sex offenders from using social media.

The suit in the nation’s highest court goes back to a seemingly harmless event in April 2010, when a man named Lester Packingham learned that authorities had dropped court proceedings stemming from a traffic ticket he had been given.

Packingham went to his Facebook page and wrote how relieved he was. “No fine. No court cost, no nothing spent… Praise be to GOD, WOW! Thanks, JESUS!” he wrote.

A police officer in Durham, North Carolina who was working to hunt down sex offenders online read the post.

Eight years earlier, at the age of 21, Packingham had been convicted of having sex with a 13-year-old girl.

He got a suspended sentence of 10-12 months and his name was placed on a registry of sex offenders. And under a much disputed law enacted in North Carolina in 2008, Packingham was barred for 30 years from using Facebook, Instagram, Twitter and all other social media.

So Packingham was convicted again, this time for using Facebook before the 30-year deadline was over. Police who searched his home after the post was read found no evidence of any new sexual misbehavior toward minors.

He appealed, saying the North Carolina law violated his right to freedom of expression.

In his legal battle over the past six years, Packingham has won the support of libertarians and groups opposing internet restrictions.

In the other corner, Louisiana and 12 other states backed North Carolina, saying it was important to block sexual predators from collecting information on potential victims.