Technically speaking, if the people really wanted to remain fully anonymous they could’ve used a VPN to login to their email and the information could’ve then pointed to a VPN service which would have to comply with the authorities. Not sure how much they have to comply with Swiss orders in those regards but it seems like this is unfortunate but not fully on Proton imo.
So it seems like it was ProtonMail that handed over the information and not their VPN service. Just for clarification.
Technically speaking, if the people really wanted to remain fully anonymous they could’ve used a VPN to login to their email and the information could’ve then pointed to a VPN service which would have to comply with the authorities. Not sure how much they have to comply with Swiss orders in those regards but it seems like this is unfortunate but not fully on Proton imo.