- On Friday, October 4, Hong Kong leader Carrie Lam announced protesters were banned from wearing face masks, as she tried to deter violent protests that have been going on for four months.
- Hong Kong isn't the only place to have banned masks at demonstrations. It's happened in the United States in response to tenant farmers back in 1845, and in the 20th Century in response to the Klu Klux Klan in the US.
- Visit Business Insider's homepage for more stories.
On Friday, Hong Kong Leader Carrie Lam announced an immediate city-wide ban on protesters wearing face masks.
She said it had to be done, because most of the protesters vandalizing the city were doing it with their faces covered. The ability to hide their identity meant protesters could evade the law and act more daring, she said.
Protesters wear the masks because they fear reprisal from China's ever-ubiquitous surveillance of dissidents, aided by the government's widespread use of facial recognition technology.
The ban was passed under an emergency law from the colonial era. It's the first time it's been used since 1967, and it was originally passed to stop a seamen's strike in 1922.
Banning masked protesters has also happened in the US, Europe, and Russia in the last two centuries.
Here are some of the places where masks or face coverings are banned in public.