The activist group Anonymous has hacked into the Ku Klux Klan's Twitter account after the hate group threatened "legal force" against Ferguson protesters.

Anonymous's trademark slogan "you should have expected us" was the first tweet from the hijacked account in #OpKKK, which looks to be the start of a lengthy war against the hate group.

A Missouri branch of the KKK called the Traditional American Knights of The Ku Klux Klan was discovered distributing leaflets (below) around Ferguson, warning that members will use "lethal force" against any protesters awaiting the verdict of the Darren Wilson case, the police officer who fatally shot Mike Brown.

Anonymous – who has long supported Ferguson protesters – warned that they would take down the Ku Klux Klan for their threats. The KKK tweeted in response that they were watching "with amusement"; two hours later, their account had been hijacked. 

The online collective will be making a full statement on the KKK account sometime today. Anonymous claims that they have looked at the direct messages on the @KuKluxKlanUSA account and stated that the account is definitely run by an official Klan member. 

Anonymous is also using the hashtags #HoodsOff and #OpKKK on Twitter to generate support for their campaign. 

The grand jury is still waiting to announce their decision on whether or not police officer Darren Wilson will be indicted for shooting Michael Brown. The results of the case, which has been heard by the court for over three months, is due any day now. The KKK has waded into the case before by helping to raise money for Wilson's defence fund in April. 

If indicted, Wilson faces four possible charge ranging from murder to involuntary manslaughter. Missouri governor Jay Nixon has already stated that he is prepared to call in the National Guard to deal with any violence resulting from potential protests.

ZDNet has received unconfirmed statements that Anonymous is doxxing KKK members and waging a phone harrassment campaign against them. Shockingly, it turns out that a member of the KKK splinter group is allegedly a police officer and another one used to be in the force.

The racist group clearly don't see the irony in criticising protesters for rioting and then threatening them with "lethal force". I guess we should have expected it.