What does the hotel need an ID card for?

1 is to prevent others from using your ID card to do other bad things.

I'm afraid you'll make trouble or have an accident, so I'll contact the public security bureau. This is a security issue.

In order to help the police solve the case, if the hotel sees the wanted ID card, it will call the police immediately to help the police catch the criminal, which is useful information.

4 is to look at age.

People come and go in the hotel, and tourists come from all directions. Some hotel staff, with incorrect ideas or something, wrote down the ID number and name in order to contact the owner of the ID card. When traveling, he saw a male staff member asking for a female tourist's ID card. The female tourist was pretty, so he would secretly write it down and write down the room, o ()) o Alas ~!

However, there are very few such people, so don't worry.