This video is currently going viral in Europe.
It shows a man executing a citizen's arrest on a man from Afghanistan who had earlier punched a 60 year old man and threatened to stab other passengers on a London train.
"Look at me! I'm strong"
I'll post sources in the comments pic.twitter.com/a2z6jY6vvA
— BasedPoland (@BasedPoland) October 4, 2019
The head butter was a Met Police officer off duty. The man had been threatening people on the train for twenty minutes before he was taken out. He was then arrested by police officers on the platform when he left the train.