Spam wars in real life use mechanisms that don’t work in fully anonymous networks like Freenet. You can’t filter by IP in a network without IPs.
Captchas are obviously not a good (or even only) anti-spam measure. But inside anonymous networks, they’re one of the few things that work. Webs of Trust, which I explicitly mentioned, are another—they just don’t scale well.
Spam wars in real life use mechanisms that don’t work in fully anonymous networks like Freenet. You can’t filter by IP in a network without IPs.
Captchas are obviously not a good (or even only) anti-spam measure. But inside anonymous networks, they’re one of the few things that work. Webs of Trust, which I explicitly mentioned, are another—they just don’t scale well.