Editor's note: The government of China's Hong Kong Special Administrative Region on Friday introduced an anti-mask law in the latest drive to end the prolonged violence.

In announcing the legislation, Hong Kong SAR Chief Executive Carrie Lam Cheng Yuet-ngor said the decision to adopt a ban is a hard but a necessary one for the public's interest.

Many countries and regions all over the world have adopted an anti-mask law. Let's take a look.