As reported by TechCrunch, the controversy was unearthed in a French police report. It revealed how ProtonMail was acting on a request sent to Swiss authorities by the French via Interpol, forcing it to hand over the IP address.
https://www.techspot.com/news/91126-protonmail-criticized-handing-activist-ip-address-authorities-leading.html?utm_source=dlvr.it&utm_medium=blogger
https://www.techspot.com/news/91126-protonmail-criticized-handing-activist-ip-address-authorities-leading.html?utm_source=dlvr.it&utm_medium=blogger