There is an old story about chewing gum in China. Back in the 90s they banned shewing gum in Tiananmen square, but the law was of course difficult to enforce.

There is an old story about chewing gum in China. Back in the 90s they banned shewing gum in Tiananmen square, but the law was of course difficult to enforce. So they made the police scrape up any dropped gum. Enforcement then happened easily enough.