TikTok is driving online frenzies that encourage anti-social behaviour in the real world, a BBC Three investigation reveals.
Ex-employees say the issue is not being tackled for fear of slowing the growth of the social media app's business.
These frenzies - where TikTok drives disproportionate amounts of engagement to some topics - are evidenced by interviews with former staffers, app users and BBC analysis of wider social media data. They have then led to disruption and disorder in everyday life.
The BBC's investigation found that TikTok's algorithm and design means people are seeing videos which they wouldn't normally be recommended - which, in turn, incentivise them to do unusual things in their own videos on the platform.
TikTok has previously distanced itself from outbreaks of disorder, such as the threatened looting of London's Oxford Street last month, which politicians blamed on the billion-user app.