Originally Posted by slowly
asking for the documents of all the guests is unreasonable, unless you visit a police state like Russia, where they have to register every foreigner living in a hotel.
Would you call, for example, Italy a police state? The requirement that every non-immigrant foreigner register with the police is not limited to Russia but a known practice in some Western European countries as well, for example, Italy.
If you were staying with a friend or relative, you would be required to go the local police department and register. However, since you are staying at a hotel, the hotel automatically registers you, and thus they need your passport details. Many guests don't know about this requirement and wonder what for they are being asked to produce their passports.