Regarding the case in question, you can find the actual warrant here, to understand what exactly happened: https://drive.proton.me/urls/57QC5F26BW#nseYl6ICaQHm

Regarding the case in question, you can find the actual warrant here, to understand what exactly happened: https://drive.proton.me/urls/57QC5F26BW#nseYl6ICaQHm https://drive.proton.me/urls/57QC5F26BW#nseYl6ICaQHm The only data we could provide (in response to a binding Swiss legal order), was the user's recovery email address, which the user added himself, and is optional to begin with. Unfortunately, the said user also used that same recovery address to create a Twitter account, and Twitter turned over his phone number and IP address. Coincidentally, this case again proves that Proton Mail's encryption cannot be bypassed by law enforcement.