I'm fairly certain we will always require privacy. If I have your credit card number and I want to use it to hurt you, I can, unless there's something else I need that I don't have, perhaps a security code. If someone can figure this out without needing privacy that'd be pretty phenomenal, but my little brain can't conceive of such a thing. And until then, we need very strong privacy.
The solution for the credit card problem would be hard but there are plenty of situation where the solution is not that inconceivable.
One way that it may work is if there is way you can trace any transaction good enough so that you can't use the credit card number without revealing yourself.
Another example would be if I'm gay. This information can be used to really hurt me in the past but not so much these days. Sure I can hide this information to prevent people to hurt me but I rather to fix the issue of the need of hiding it in the first people.
I would imagine if people can hide being gay perfectly there wouldn't be that much acceptance today.
I agree it would be best to address the reasons why people hurt each other with information (such as someone who is gay) but the unfortunate reality is that will never happen, not until 100% of our population is virtuous, and that’s impossible. And while it may be less damaging today to be identified as gay than it was 20 years ago, in the United States it is now becoming more damaging to be in the majority than it was 20 years ago. As far as I understand Marxism, it’s Marxism: the oppressed will overthrow the oppressor and will become the new oppressors. We’re just trading oppressors, and while it may seem justifiable to oppress the old oppressors, it doesn’t address the issues that people and not virtuous.
I’m concerned you’re grossly naïve if you think this can happen. It isn’t a matter of effort. Yes it will require all of the population to be virtuous, otherwise a single friend, or even acquaintance can hurt someone because of what they know. How is that not obvious? They can mock someone for their preference of beer, or sexual identity, or height, etc to such an extent that they would commit suicide.