Forbes: https://www.forbes.com/sites/thomasbrewster/2023/08/08/protonmail-fbi-search-led-to-a-suspect-threatening-a-2020-election-official/?sh=48791539235c

• Claire Woodall-Vogg, the executive director of the Milwaukee Election Commission, was harassed and threatened after an innocuous email exchange with an election consultant was published by conservative news outlets.
• One of the harassers used ProtonMail, an encrypted email service, to send Woodall-Vogg a threatening email.
• The FBI acquired data from Proton Technologies, the owner of ProtonMail, to help them identify the anonymous emailer.
• The FBI was able to find the suspect’s identity and conduct a sweep across their internet accounts, but they were not charged with any crimes.
• Woodall-Vogg said that the harassment has not continued recently.
• ProtonMail said that they employ several teams to handle instances of abuse on their platform and that they only provide metadata to law enforcement agencies.
• ProtonMail has received 6,995 orders for data in 2022, of which it contested 1,038.

They said in the past that to retain anonymity, users should use Tor to access the service.