You’ve done it now, Lizard Squad. We can confirm that you’re under investigation.

The Federal Bureau of Investigation has started investigating Lizard Squad, the online group that took credit for knocking PlayStation Network and Xbox Live offline. On Christmas, Lizard Squad allegedly assaulted Sony’s and Microsoft’s servers with a distributed denial-of-service (DDoS) attack, which overwhelms a target with junk data that most servers can’t handle. The result was that PlayStation and Xbox owners couldn’t play many games or use online services for extended periods of time — potentially costing the companies millions of dollars in lost transactions and damages.

“The FBI is investigating the matter,” a spokesperson for the bureau told GamesBeat. “Given the pending nature of the case, we cannot comment further.”

DDoS attacks are illegal if they cause a certain amount of damage. With Sony and Microsoft unable to sell digital games through their online stores during their outages, Lizard Squad’s actions would qualify for a criminal case. That does not even take into account the repairs and maintenance Sony and Microsoft may have needed to get their Web services back up online.

Lizard Squad is at least pretending not to care about an FBI investigation. Rumors of the feds’ involvement had popped up previously, and the group responded with following tweet:

The Internet vandals have used the publicity it is getting for the PSN and Xbox Live hacks to launch a DDoS-for-hire service where you can pay the group $6 to attack the site of your choice. That is not the only way Lizard Squad has profited from its activities. On Friday, Kim Dotcom, the owner of popular for-transfer site Mega, gave Lizard Squad 3,000 lifetime passes to Mega. The group is reportedly selling those certificates for $30 each.