Notorious hacker group Lizard Squad has moved on from attacking Xbox Live and the Playstation Network and has now set its sites on the Tor network.

The group announced the zero-day attack on Twitter, where is said it would target unnoticed weaknesses.

To clarify, we are no longer attacking PSN or Xbox. We are testing our new Tor 0day.

— Lizard Squad (@LizardMafia) December 26, 2014

The Tor network uses globally distributed nodes to protect the anonymity of users, allowing the origin of data to be obscured. As a the time of writing, Lizard Squad would appear to have taken over the majority of Tor’s nodes, which would give it the ability to breach Tor anonymity.

There’s a total of ~8,000 Tor relays – @LizardMafia now owns almost half of them. Big implications on Tor anonymity. https://t.co/6RhTLqDS2p — Nadim Kobeissi (@kaepora) December 26, 2014

Despite Tor originally being designed to provide anonymous communication to users living under oppressive regimes (it actually started a a U.S. Naval Research Laboratory project and counts the Department of State as a sponsor) it’s perhaps better known publicly as a place where drugs and child porn are traded, and this appears to be the motive for the attack.

Only hackers, miscreants and pedophiles use Tor.

— Lizard Squad (@LizardMafia) December 26, 2014

It’s not clear how far the attack will compromise anonymity at least today; The Verge quotes an expert stating that “The attack won’t be effective unless Lizard Squad’s relays obtain enough consensus with the rest of the network, which is currently not happening due to the newness of the relays and their low bandwidth allowance.” New nodes have restricted bandwidth but gain more with time, suggesting that if it isn’t bad now, it will certainly get worse.

If you are a Tor user our advice to you today: if you value your anonymity consider not using the network until the issue is sorted out.