G20 organisers are preparing for a barrage of possible cyber attacks, with fresh threats from hacktivist group Anonymous to hijack G20 social media.

Anonymous Galactic, a branch of the global hacktivist movement, called on its members to “hijack” the G20 hashtag on social media today, to bombard Twitter and Facebook with “negative comments.”

“The #G20Brisbane hashtag is taking off on Twitter and Facebook now so it’s a good time to hijack it, I’ve noticed a lot of negative comments towards the G20 looking at the hashtag already which is great, so lets (sic) add to them,” the group posted on Facebook.

“Over the G20 weekend the hashtag #G20 will be smashed by the Media and on both Twitter and Facebook. We have done this before. Lets hijack the hashtag online and show the world the truth.”