This was covered here
I was going to use ProtonVPN as well but in email exchanges they refused to answer how they would prevent a malicious actor simply purchasing a new subscription if their account is banned, they said they can’t give the information as they need for some elements of the service to remain secret in order to prevent abuse. This makes my paranoia spike and creates a concern that perhaps they generate a unique User ID for every subscriber through fingerprinting hardware and display details, meaning the fingerprint ID of the “new” subscriber would match that of a previously banned user