Switzerland has its own DNS blocklist that all ISPs obey. [1]
Quad9 doesn't obey it but I never understood how they can get away with that legally. I'd be interested in an explanation if someone knows more!
1. https://www.gespa.ch/en/fighting-illegal-gambling/access-blo...
Sounds like they get away with it legally because the law applies to ISPs and they’re not an ISP.
From your link:
> Internet service providers in Switzerland are obliged to take measures to prevent access to these domains (DNS blocking).
I opened the blocklist expecting some juicy Linux ISO sites and... it's all betting sites. I'm not even mad.
Quad9 is not a telecommunications service provider as defined by Swiss law, which is where that application becomes enforced. Details of this (and many other things) can be found on the "Compliance and Applicable Law" section of the website. https://quad9.net/privacy/compliance-and-applicable-law/