An 18-year-old man was arrested this morning in Merseyside County in northwest England as part of an investigation into the attacks, which knocked the gaming systems offline, as well as "swatting" offenses, police said. Swatting is when someone falsely reports a crime to law enforcement to prompt a SWAT team mobilization.
Police in the United Kingdom typically do not release the names of suspects at the time of their arrest.
"We are still at the early stages of the investigation and there is still much work to be done. We will continue to work closely with the FBI to identify those to who commit offences and hold them to account," Craig Jones, head of the regional cyber crime unit, said in a statement.
Microsoft's Xbox Live and Sony's PlayStation Network both suffered “distributed denial of service” attacks over Christmas, designed to flood the networks with artificial traffic, ultimately disrupting connectivity and knocking the systems offline.
Lizard Squad, a mysterious hacking collective that seems to choose its targets for the "fun" of it, tweeted at the time that it was responsible for the attack.