MANILA - Citing "coordinated, inauthentic behaviour," Facebook has removed 200 pages, groups and accounts linked to a network organised by President Rodrigo Duterte's former social media handler.

In a notice posted on Thursday (March 28), Facebook cybersecurity policy head Nathaniel Gleicher said 67 pages, 40 groups and 68 accounts were removed. A further 25 Instagram accounts were also shut down.

One page had at least 3.6 million followers, while over 1.8 million accounts joined one group. Some of the Instagram accounts, meanwhile, were reeling in about 5,000 followers.

Mr Gleicher said the pages, groups and accounts were "misleading others about who they were and what they were doing".

These were taken down "based on their behaviour, not the content they posted", he said.

He added that the "the people behind this activity coordinated with one another and used fake accounts to misrepresent themselves". Much of the content were political in nature and slanted in favour of the Duterte administration. These heaped praises on pro-Duterte candidates running in the midterm elections in May, attacked opposition politicians, and lambasted former president Benigno Aquino and his allies.

Mr Gleicher said an investigation traced the pages, accounts and groups to Mr Nic Gabunada, a former senior vice-president at top broadcaster ABS-CBN.

In past interviews, Mr Gabunada revealed that he was handed 10 million pesos (S$260,000) to run Mr Duterte's social media campaign in 2016.

A study by the University of Oxford confirmed the amount, and Mr Duterte himself had said his campaign probably shelled out even more.

But Mr Gabunada insisted his social media strategies had all been "above-the-line", and that he had never resorted to using trolls or fake accounts.

The Oxford study, though, concluded that Mr Gabunada had used bots and paid hundreds of "influencers" to "flood social media with pro-Duterte comments, popularise hashtags and attack critics".

During the 2016 campaign, Facebook docked complaints about Mr Duterte's online supporters circulating aggressive messages, insults, threats of violence, and later false information, including a fake endorsement by Pope Francis.

Mr Duterte ended up dominating the political conversation so thoroughly that in April, a month before the vote, a Facebook report called him the "undisputed king of Facebook conversations". He was the subject of 64 per cent of all Philippine election-related conversations on the site.

Millions of "keyboard trolls" are still being used to "spread and amplify" Mr Duterte's policies, now that he is in office, according to the Oxford study.

Mr Gleicher told reporters that despite the heavy political content of both his fake and real accounts, Mr Gabunada was considered a "non-government actor".

Facebook "(doesn't) have anything concrete linking the Gabunada-run network to the government", he said.

A senior official of the social media giant said in January (2019) that Facebook was taking down bogus accounts and preventing the spread of false information to protect the integrity of the Philippines' midterm elections in May.

"The goal of Facebook in elections is to make it harder to interfere with elections on the platform, and easier for people to make their voices heard in the political process," Facebook's head of global politics and government outreach Katie Harbath said in a news conference.

Facebook in January (2019) banned digital marketing group Twinmark Media Enterprises from its platform, and shuttered over 300 of its pages and groups. At least one page had some 43 million followers.

Twinmark was found to have violated Facebook's policies on misrepresentation and spam, as it used fake accounts, led people to ad farms, and sold access to pages to artificially increase distribution and generate profit.

One page was reported to be earning at least US$100,000 (S$135,000) a month.

A popular page was Trending News Portal, which generated questionable news articles that were widely shared by Mr Duterte's supporters.