Beyond CAPTCHAs: How do we keep human‑pretending bots out of the fediverse?

CAPTCHAs and sign‑up quizzes annoy real people and barely slow down determined bots. As the fediverse grows, we need smarter, more humane defences, ones that don’t push away genuine newcomers. What creative, non‑intrusive ideas do you have? Trust‑based vouching, proof‑of‑humanity protocols, behavioural signals... what feels both effective and aligned with the open social web? I’m building a social media platform and I'd love to hear your thoughts on this topic.