The case of the French activist was a useful wake up call for many. They were arrested as a result of information relating to email account creation, and identification of the device used .
Essentially, Swiss courts will force Proton to provide all available information if a crime has been "established". Remember, new legislation is created daily, and comes into effect straight away.
In this case the activist was campaigning about gentrification.
Proton have since provided other documentation clarifying ways to avoid them having any useful information to give; however, you won't usually notice that stuff on the front page of advertising for many service providers.
At least nobody disappeared in this case.
Thanks for the stimulation SGOTI.