The hackers group called Lizard Squad which also claims responsibility for taking down PlayStation Network and Xbox Live over the Christmas Holiday, tweeted that they are behind the Tor Browser Cyber Attack from Friday.

Right after Lizard Squad claimed the Tor attack, The Anonymous Group posted a message related to this attack. They told Lizard Squad to stop the attack as soon as possible, because “People need that service because of corrupt governments”:

In it’s latest tweets, the Anonymous Group is trying to explain what is Tor and how it works. You can find more information regarding the Tor Browser by watching this video:

 

UPDATE

Tor Browser’s team posted a statement regarding the way they were attacked:

[tor-talk] 3347 “lizardNSA” Relays on google cloud.

It is dangerous. I’ve run a cluster of exits for a long time and
people like myself and Moritz know the dangers of reducing the
diversity pool. Adding even a gigabit of exits to a single AS right
now is dangerous and I’ve consulted arma on the topic before who
agreed. Beyond 25% of the network is dangerous and higher than that
could cause serious anonymity implications.

As a correction too, you do not control 90% of the exit BW, you have a
potential of approximately that. If, what I only really described as a
Sybil attack continues (I can’t judge if it is malicious as there is
no evidence of that to my knowledge), it will harm the Tor network and
it does run the risk of getting a BadExit flag.

Also, if you want to contribute to Tor you are welcome to ask what to
do. Coming in, firing up huge B/W potential exits without blocking
certain ports and then associating it as a positive sign is to
misunderstand why the network is secure and can be very detrimental to
our cause. We can cope with double the bandwidth before those nodes
came online and we can certainly scale – me and Moritz, as well as
other groups who work on Tor in various ways do have plans should this
ever be required even on short notice.

Source – https://lists.torproject.org/pipermail/tor-talk/2014-December/036185.html