If you pay Proton Mail for a service, they may hand over the payment data in response to a court order: https://www.404media.co/proton-mail-helped-fbi-unmask-anonymous-stop-cop-city-protestor/
Proton Mail Helped FBI Unmask Anonymous ‘Stop Cop City’ Protester

A court record reviewed by 404 Media shows privacy-focused email provider Proton Mail handed over payment data related to a Stop Cop City email account to the Swiss government, which handed it to the FBI.

404 Media
@evacide It's even worse if you pay for Proton Mail and live in CH like I do (also citizen). It means they'll just turn my sh*t over to Bern. I wonder if they'd even inform me.
@rashunda @evacide *Any* Swiss company will comply with a court order (as will other companies in other countries).