Facebook and Twitter are cracking down on what they say is a China-backed disinformation campaign to "undermine" ongoing protests in Hong Kong.
Huge demonstrations have been staged in the former British territory in recent months over proposed legislation that would allow authorities to detain and extradite people wanted in countries Hong Kong did not already have agreement with, including mainland China.
Although the controversial bill has since been suspended, a refusal to completely withdraw it has seen the protests continue and escalate – with organisers estimating that at least 1.7 million took part in a rally on Sunday.
China has been heavily critical of the demonstrations, and Facebook and Twitter have revealed that they are working to block efforts from within the country to undermine the movement through disinformation – which the latter said was an attempt to sow political discord in Hong Kong.
Twitter announced that it had removed 936 accounts that were behaving in a co-ordinated manner to amplify messages related to the Hong Kong protests, with Facebook removing five accounts, seven pages and three groups it said were engaged in a number of deceptive tactics.
Both social networks are blocked in China and Twitter said many of the accounts it had banned were accessing the platform via a virtual private network (VPN), which allows users to bypass such restrictions.
Others were able to tweet from specific unblocked IP addresses originating in mainland China.
Twitter said the accounts it had banned were the most active portions of a co-ordinated state-backed operation that involved some 200,000 profiles, many of which have been created since the suspensions.
It added: We will continue to be vigilant, learning from this network and proactively enforcing our policies to serve the public conversation. We hope that by being transparent and open we will empower further learning and public understanding of these nefarious tactics.
Facebook, which took action after a tip-off from Twitter, said at least one of the pages it had removed had about 15,500 followers, while one of the groups had about 2,200 members.
Among the content being posted were memes comparing the protesters to cockroaches and armed terrorists, with one post saying that they shoot to kill with a slingshot and took a nurse’s right eye.
Facebook said: We’re constantly working to detect and stop this type of activity because we don’t want our services to be used to manipulate people. We’re taking down these pages, groups and accounts based on their behaviour, not the content they posted.
As with all of these takedowns, the people behind this activity co-ordinated with one another and used fake accounts to misrepresent themselves, and that was the basis for our action.
We are making progress rooting out this abuse, but as we’ve said before, it’s an ongoing challenge. We’re committed to continually improving to stay ahead.