They don't need to enumerate every possible ways. They were misleading in their previous marketing material. They since changed it, but here is what they had on their Security Feature page:
> Anonymous > No tracking or logging of personally identifiable information > Unlike competing services, we do not save any tracking information. By default, we do not record metadata such as the IP addresses used to log into accounts. As we have no way to read encrypted emails, we do not serve targeted advertisements. To protect user privacy, ProtonMail does not require any personally identifiable information to register.
They do log IP addresses and do offer them to law enforcement.
Now they only say this:
> Opt out of tracking or logging of personally identifiable information
This is still misleading, as the IP address is definitely an identifiable information, as shown in this case, but also because the section is still called "Anonymous".
> This, though, seems to me to be pretty unambiguously a situation where personal responsibility needs to take over.
I disagree so hard on that. ProtonMail is used in extreme cases. In cases where they have no technology knowledge, even the existence of IP address, in situations where they may not know Swiss laws, nor are aware of some first world countries laws and are only aware of their own countries more fascist laws. They are selling an anonymous service, which isn't...
The biggest issue is that there's way to actually be anonymous (or at least, closer to be), using TOR, and that's how they should sell their service.
So yeah I disagree that it's fine that they are selling a service that they can't sell in theses conditions...