In the last year or so, there have been attacks by separatist Uygurs aimed at the Chinese government. The Uygurs are natives in the Xinjiang region of China, the furthest Northwest of the country. They are bordered by Kazakhstan, Kyrgyzstan and Pakistan. Many of the Uygurs do not consider themselves to be part of China, and have maintained their own language and culture. China considers Xinjiang to be part of China, and have enforced Mandarin as the official language, and Chinese government rule. The Uygur fighters have a history of being great horsemen and great swordsmen. Sort of like in the old Sinbad or Aladdin movies. So when the Uygurs launch a terrorist attack, often it is with knives. There was an attack on a busy rail station last year, and many people were killed in random knifings. Really terrible. So now, there are restrictions on knife purchases at the large grocery / department stores. But if you go to a high-end expat market, you can buy knives without any problem. I guess the government doesn't feel the foreigners are a risk
There are two kinds of toilets in many Chinese restrooms.