The app that has 19 million daily US users faces an impending ban on 'transactions'. Phoebe Zhang in Shenzhen reports on how this impacts Chinese iPhone users; Professor Wanning Sun unpacks how the Chinese diaspora in the US used WeChat in support of Trump, and the political 'revolution' during the Black Lives Matter protests; Ron Diebert from Citizen Lab reveals the investigations into WeChat surveillance and use of user's posts and data.