@troed @privateger @Gina
https://web.archive.org/web/20210123101755/https://eprint.iacr.org/2018/1121.pdf
https://web.archive.org/web/20210907033657mp_/https://protonmail.com/blog/transparency-report/
Upon receiving a judicial order, ProtonMail is obliged to provide any user information readily available that would help identify a user that is subject to a criminal investigation that has been validated by Swiss authorities. In addition to the items listed in our privacy policy, in extreme criminal cases, ProtonMail may also be obligated to monitor the IP addresses which are being used to access the ProtonMail accounts which are engaged in criminal activities.
http://web.archive.org/web/20210907022818/https://techcrunch.com/2021/09/06/protonmail-logged-ip-address-of-french-activist-after-order-by-swiss-authorities/?guccounter=1So, in the specific case, it looks likely that ProtonMail was either under legal order to delay notification to the account holder — given what appears to be up to eight months between the logging being instigated and disclosure of it — or it had been provided with information by the Swiss authorities which led it to conclude that delaying notice was essential to avoid a risk of “injury, death, or irreparable damage” to a person or persons (NB: it is unclear what “irreparable damage” means in this context, and whether it could be interpreted figuratively — as ‘damage’ to a person’s/group’s interests, for example, such as to a criminal investigation, not solely bodily harm — which would make the policy considerably more expansive).It’s that IP monitoring component which has caused such alarm among privacy advocates now — and no small criticism of Proton’s marketing claims as a ‘user privacy centric’ company.It has faced particular criticism for marketing claims of providing “anonymous email” and for the wording of the caveat in its transparency disclosure — where it talks about IP logging only occurring in “extreme criminal cases”.