[jdietrich]

>This type of behaviour should be banned by the European Union.

It probably already is. Under Article 15 of the GDPR, you have the right to access personal data and to an explanation of how that data will be processed. A database entry saying "this account has breached clause x.y of our ToS" constitutes personal data within the scope of GDPR.

Under article 16, you have the right to correct any inaccurate data. Under Article 22, you have the right to opt-out of any wholly automated decision-making process that "produces legal effects concerning him or her or similarly significantly affects him or her".

Article 23 does impose some restrictions on those rights, e.g. in matters of national security, defence or criminal justice, but those restrictions are narrow and specific. If someone tells you "your account is banned and we can't give you any further information", they're likely in breach of the GDPR.

https://gdpr-info.eu/chapter-3/