2016 is a big election year. But something is going very wrong online. Journalists in America and the Philippines start to notice something strange going on online.

In Manila, Maria Ressa - the editor of online news site, Rappler - discovers a sock puppet network of social media accounts, all pushing for the election of a strong leader. Someone like Rodrigo Duterte. Maria is suspicious. She makes an urgent call to Facebook.

In Veles, in Macedonia, a young man called 'Marco' starts writing fake articles and posting them online. Very soon they're being read by millions of people around the globe and he's making huge sums of money.

The online ecosystem is under attack.

Producer: Caitlin Smith
Sound design and mix: Eloise Whitmore
Composer: Jeremy Warmsley
Exec: Peter McManus
Researcher: Juliet Conway and Elizabeth Ann Duffy
Commissioned by Dan Clarke

Archive: BBC News, AP Archive, Bloomberg Television, CNN

New episodes released on Mondays. If you’re in the UK, listen to the latest episodes of The Gatekeepers, first on BBC Sounds: bbc.in/3Ui661u