I agree. Much like the email reputation systems that evolved over time, I think other companies (like Google/FB/etc.) will eventually create hidden "reputation scores". For brand-new (maybe throwaway) accounts, those scores will harm the ability to participate in many places. After cultivating reputation (sending emails that don't look sketchy, talking to people who are deemed likely--by IP/demographics/click habits--to be your real-life peers), more participation in different communities will be allowed. Situations where reputation is insufficient for participation will be shadowbans more often than not.

This type of system solves a lot of the throwaway-for-purposes-of-evil-behavior problem, and may well be able to do that algorithmically, in lieu of human moderators. In return, it requires people to give up a lot of privacy/anonymity to participate. I don't think that's an inherently good or bad tradeoff, but it is definitely one people should be aware of.