So I've been thinking today, let's say you open up a bank account. Then you decide you want your data to be completely erased. Banks obviously can't do that immediately because of the law, because they need to keep your data for 5-10 years. So okay, 5-10 years go by, and you decide you want your data to be completely erased again (GDPR). After the deletion, is there any proof at all that you've been a bank's customer? I mean they have to do a complete clean up, or are there any exceptions when it comes to such situation? I've been googling a bit but no luck.