Protonmail doesn’t have a past of bad behaviour per se - they do comply with legal subpoenas from the Swiss authorities (they are based there) but as emails are user-key encrypted and they don’t keep a copy of the user key, the most they can provide is IP addresses and dates.

There was some stuff that went down with regards to a French activist but nothing that puts Protonmail at fault (again, legally binding court order, they literally had no choice)