https://www.vice.com/en_us/article/88njdg/protonmail-under-fire-for-sharing-clactivist-data-with-french-authorities

Encrypted email provider ProtonMail is under intense scrutiny for sharing the IP address and device details of a French climate activist with French authorities, and for marketing and transparency reports critics say provided users with a false sense of anonymity and security. A French police report, first spotted by Techcrunch, indicates ProtonMail provided law enforcement the IP address and device details of a French activist protesting gentrification and climate inaction in Paris. The group drew significant attention for occupying Le Petit Cambodge—a restaurant targeted in the November 2015 terrorist attacks on the French city. 

Last week, the group issued a statement on Paris-luttes.info, an anticapitalist news site, outlining various police inquiries into the group. One inquiry involved French police sending a Europol request to ProtonMail, demanding the name of the creator of an email account used by the group for public communications. Switzerland-based ProtonMail isn’t traditionally subject to French or European law enforcement requests. But the service does have to comply with demands from the Swiss court system, which required it to begin logging user IP information after receiving a request from Europol. Once that data was collected, the activist was identified and arrested.