The US Supreme Court struck down a California law prohibiting sales of violent video games to minors, saying the ban is an unconstitutional infringement on speech rights.

The court yesterday rejected the state’s contention that violent games are akin to sexual materials, which the government can restrict to protect children.

“Even where the protection of children is the object, the constitutional limits on governmental action apply,” Justice Antonin Scalia wrote for five justices. The vote to strike down the law was 7-2, with the majority divided in its reasoning.

A decision upholding the law, which was never enforced, might have encouraged enactment of similar measures around the country. The video game industry has more than $10 billion in annual sales.

Two industry trade groups, the Entertainment Merchants Association and the Entertainment Software Association, challenged the law. Members of the two groups include Electronic Arts, Microsoft, Sony and Take-Two Interactive Software, the maker of “Grand Theft Auto” games.