Why do I need a copy of my ID card to book a hotel in Hong Kong?

The hotel needs to make a copy of the ID card, because the public security requires it to be kept. The hotel needs to copy its ID card and be filed by the police. Sometimes the ID card is degaussed and cannot be scanned, so it can only be copied and entered into the hotel system later. So you need a copy of your ID card to book a hotel in Hong Kong. The Hong Kong Special Administrative Region is one of the regions with the highest population density in the world, with the highest life expectancy and the fourth highest human development index in the world.