Hackers took down online gaming services that plagued console owners on Christmas Day.
Tens of thousands of new Xbox One and PS4 owners were unable to log in to try out their new games.
Twitter accounts under the name Lizard Squad asked followers to retweet or follow postings to get services back online. At around 1am one account said: "Attacks have stopped", but later it claimed PlayStation was down again.
Last month hackers broke into Sony's systems and stole huge amounts of data, apparently in retaliation for The Interview, a movie about a plot to kill North Korean leader Kim Jong-Un.
The movie was screened in the US on Christmas Day, and is now online.