Hackivitst group Anonymous has joined those condemning the terror attacks in Paris on Friday night and vowed to hunt down those responsible online and expose them.

Anonymous, a loose collection of online activists, has been tracking the online activity of Islamic State group supporters for some time as part of a campaign to expose and shut down Twitter accounts used by the group to communicate and spread its message globally. Now, Anonymous is looking to take specific action against ISIS, which has claimed credit for the attacks in Paris that left 129 people dead, 42 fighting for their lives and over 400 more injured.

A video posted online by the group, which has since been removed, shows a member from the group speaking in French and wearing the iconic Guy Fawkes mask

Anonymous from all over the world will hunt you down. You should know that we will find you and we will not let you go. We will launch the biggest operation ever against you.

The group has since added an English language version which is still online and can be seen below:

Calling the action Operation Paris, or OpParis, the group says it wants members of Anonymous to avoid its typical tactic of launching distributed denial of services (DDoS) attacks against ISIS websites, but instead to attack to hack into the sites to steal valuable information and lead it online.

According to the main Twitter account associated with the campaign, the group has already successfully taken over 2250 pro-ISIS Twitter accounts offline.

The group launched a similar campaign in the wake of the Charlie Hebdo massacre in January and within days claimed its first victory by knocking an extremist website offline. The group has in the past been accused of leaking misleading information and as part of OpISIS earlier this year, a number of the accounts it claimed were associated to ISIS were shown to be inaccurately grouped with those belonging to ISIS sympathizers.