As any other company operating legally, we have to respect the local legislation, which is what happened in this case. The case also shows that our encryption works as intended - we were not able to share any of the user's data stored encrypted on our servers (email content, attachments, etc.), because we don't have access to it ourselves.
Note also, that the case pertains to Proton Mail, and not Proton VPN. Proton Mail is considered to be a communication service, and in most countries (including Switzerland), communication services are regulated to some extent. The treatment of VPNs is different. There are no Swiss laws compelling us to log IP addresses, personal identifiers, traffic or browsing history, as proven in a 2019 legal case (we were not able to provide the requested information because we don't keep any: https://protonvpn.com/blog/transparency-report/).
Note also, that the case pertains to Proton Mail, and not Proton VPN. Proton Mail is considered to be a communication service, and in most countries (including Switzerland), communication services are regulated to some extent. The treatment of VPNs is different. There are no Swiss laws compelling us to log IP addresses, personal identifiers, traffic or browsing history, as proven in a 2019 legal case (we were not able to provide the requested information because we don't keep any: https://protonvpn.com/blog/transparency-report/).