Earlier quoted context omitted.
> It's a way to authenticate yourself without a centralized authority PGP did that 31 years ago though, faster and more efficient and without all the downsides?
inefficiency here can actually be useful, it's similar to password stretching. If you know someone had to burn $10 of electricity to make an authentication, it hurts more to get banned.
Metafilter charges $5 to get an account. If you can't afford the $5, you can email the mods to join for free.
SomethingAwful charges $10 (and offers a platinum account, and a paid add-on to view old threads).
Both of these payments are done through PayPal, and both exist as a way to filter spammers and trolls.
I thought the whole point of decentralisation was that you couldn't be banned though.