What connects amateur sleuths turning up at crime scenes, anti-social behaviour in UK schools and riots in France? A new BBC documentary finds evidence they are all examples of TikTok “frenzies”.The BBC’s disinformation and social media correspondent, Marianna Spring, has spent the last year investigating harmful behaviour on TikTok spilling out into the real-world.As well as crunching the numbers, Marianna tracks down TikTok users, victims and former employees to interrogate and expose how extremely high engagement on TikTok around particular topics appears to be creating these “frenzies”.The documentary explores how users go to extreme lengths in order to get more engagement in a battle for followers and likes. Marianna investigates the role TikTok's algorithm and format plays in what’s happening and reveals insiders’ concerns about the app.The documentary seeks to find out if this the real danger of TikTok and what impact it is having on society.