Jack Dorsey
© Reuters / Anushree Fadnavis
Twitter CEO Jack Dorsey (November 2018 file photo)
As mainstream media outlets accused Twitter of allowing a Chinese news agency to advertise its reporting on the Hong Kong protests, the platform announced it would ban all "state-controlled" media advertising within a month.

"Going forward, we will not accept advertising from state-controlled news media entities," Twitter announced on Monday afternoon.

What exactly amounts to a "state controlled" media will be "informed by established academic and civil society leaders in this space," Twitter said.

The devil, as usual, is in the details. The policy will not apply to "taxpayer-funded entities, including independent public broadcasters," the company said, in language that seems tailor-made for outlets such as the BBC or Voice of America (VOA), and seems both broad and flexible at the same time, to the point of being arbitrary.

The authorities Twitter intends to rely on in defining "state media" were listed as Reporters Without Borders, the Committee to Protect Journalists, the UK-based Economist magazine's Intelligence Unit, the Dutch-based European Journalism Centre, UNESCO, and the US government-funded NGO Freedom House.

Determination will depend on criteria such as "control of editorial content, financial ownership, influence or interference over broadcasters, editors, and journalists, direct and indirect exertion of political pressure, and/or control over the production and distribution process," Twitter said.

The announcement comes on the same day as a number of reports in mainstream media outlets that accused Twitter of accepting advertising buys from the Chinese news agency Xinhua, which was critical of protesters in Hong Kong.

Also on Monday, Twitter announced it had "proactively" shut down a number of Chinese accounts critical of the Hong Kong protests.

The unrest in Hong Kong began at the end of March, over the proposed bill to allow extradition of criminal from the autonomous city to the mainland, and continued after the bill was suspended, with protesters waving US and British flags while demanding "freedom, human rights and democracy."