Looks interesting but

We propose solving the spam problem by having each subplebbit owner run a “captcha service” node over peer-to-peer pubsub. Peers who fail too many captchas are blocked from pubsub.

Seems to want heavy use of Captchas. I’m not sure I like that idea.

Anytime you have a new architecture, it’s all about trade offs. I don’t fully understand these yet.