In Switzerland you are forced to receive an SMS code to your phone on every portal in every public space everywhere to establish your identity on every network. No SMS = No public wifi anywhere in Switzerland.
That's a funny choice, I thought Europe was done with SMS. I can see this 1-to-1 mapping with other cellphone derived messaging like Whatsapp, etc being an issue for privacy but it's certainly possible to have multiple phones.
How would an SMS code sent to a phone number be traced to the specific user? Anonymous VOIP numbers are plentiful.
The reason is that the law in Switzerland requires identification of the user of free internet services [1]. So it is not just common practice
[1] https://www.gva.ch/Site/Passagers/Shopping/Services/Business...