[soylentcola]

I can't think of a world where I would trust such a system (or trust anyone to create/run such a system). Is this just for websites? Or does it encompass all use of the Internet?

At least as far as websites or individual platforms go, this is exactly what accounts, moderation, and "banning" already attempt to do. We've seen how difficult and expensive this is to scale when your site gets as big as Facebook or Reddit. I can't fathom a sufficiently "benevolent dictator" that I would trust to act as a gatekeeper for the entire Internet at large.

[e2le]

Perhaps a potential solution is POW based registration, registration is slow and CPU heavy. I don't think it's likely there is going to be a perfect solution to this and might be that it's better to slow down bad users and make it expensive to ban evade.

[ChainOfFools]

This will just end up promoting the interests of already wealthy bad actors, and fomenting user cartelification behind a screen of anonymity. See also: Bitcoin

[Zaak]

That's a very interesting idea, though it wouldn't significantly affect people with vast resources such as botnet owners, corporations, and governments. It would certainly slow down the garden-variety troll, however the determined troll would just keep a core burning to create a steady stream of sock puppet accounts.