A group of hackers knocked out a number of popular online video game servers, including the popular Sony Playstation network.
Hackers calling themselves “Lizard squad” claim responsibility for taking down PSN, as well as networks for “World of Warcraft,” League of Legends” and other multi-player games.
Those services allow millions of gamers to play together over the internet.
The targeted companies say hackers used a “Distributed Denial of Service” or “DDOS” attack, to overwhelm the networks with web traffic.
The FBI says it is investigating the hacks.
On its Twitter account, Sony said late Sunday most of its services were restored.
In a related twist, the hackers also claim they made threats against an American Airlines flight with a Sony executive on board.
That flight was diverted to Phoenix as a precaution.