Anonymous is one of the fightiest groups on the internet. The loose collective of hacktivists, born from the notorious 4chan forum, has declared war on nearly every hate figure imaginable, from Scientology in 2008 to, most recently, Islamic State. Here are some of its most notorious clashes.

Isis

Why: Initially, the Charlie Hebdo murders, but the opposition was stepped up following the Paris attacks on Friday.

What it said: “You, the vermin who kill innocent victims, we will hunt you down like we did those who carried out the attacks on Charlie Hebdo.”

What it did: A crowdsourced campaign to identify and report Isis supporters and propaganda videos on social media, as well as bring down websites using distributed denial-of-service attacks.

Anonymous 'at war' with Isis, hacktivist group confirms Read more

Church of Scientology

Why: The attempted suppression of a video featuring Tom Cruise promoting the religion.

What it said: “We shall proceed to expel you from the internet and systematically dismantle the Church of Scientology in its present form.”

What it did: The clash led to the formation of Anonymous, and saw protesters outside Scientology centres worldwide. The church’s habit of filming protesters and disseminating video footage directly led to the adoption of the Guy Fawkes mask that is now a central part of the group’s iconography.

Atlantic Records

Why: The record label wouldn’t confirm a release date for a delayed album by the rapper Lupe Fiasco, which the group saw as censorship.

What it said: “You have 24 hours to present a statement announcing the immediate release of [Tetsuo & Youth]. If you do not comply, we will launch a direct attack against your website, your associates, and your executives … Blatantly censoring @LupeFiasco is inexcusable.”

What it did: In the end, nothing. Atlantic Records announced a release date 19 hours later, and Anonymous claimed victory.

Ku Klux Klan

Why: The group threatened to hurt protesters in Ferguson, Missouri.

What it said: “We are not attacking you because of what you believe in, as we fight for freedom of speech … The Ku Klux Klan is a terrorist group. The blood of thousands of human beings is on the hands of the Klansmen.”

What it did: A long-running campaign of deanonymisation. Anonymous has been attempting to uncover the identities of Klan members since November 2014, and earlier this month released the latest tranche of accused Klan supporters.

Government of Cambodia

Why: The country arrested two members of Anonymous Cambodia over hacking allegations.

What it said: “You have made an enemy of Anonymous. You have angered us considerably and we now pose a significant threat to you. You have once again disregarded the requests of the people, and continue to operate for your own unfair, selfish and pathetic gain.”

What it did: Hacked Cambodian government and military websites, and claimed to have stolen the data of mobile phone users from the country’s biggest carrier, Cellcard.