It seems like giving instances the ability to filter interactions with instances/users that don’t have Captcha seems necessary.
I noticed the admins are working on mCaptcha (proof of work based captcha) for user registration, if filtering at account creation isn’t enough, maybe requiring a PoW hash like this for any interaction could help with the bot problem? I don’t know how ActivityPub works though…
Yeah this seems to be the idea behind mCaptcha and other proof of work based solutions. I noticed the developers were working on adding that to Lemmy