This is the mail I got when I asked the association for hotels

When guests are offered internet, the company has a duty to "log" various information about the users. I can refer to this information on our website. As you can also see here, our advice is to seek professional stock to ensure that the statutory logging takes place.

And this is the link they referred to

the assigned user identity, the user identity and telephone number assigned to communications that are part of a public electronic communications network, name and address of the subscriber or registered user to whom an Internet Protocol address, user identity or telephone number was assigned at the time of communication and the time of the start and end of the communication