From the top comment on Hacker News:

(d) flooding of the internet with garbage. This might be the worst one in the end. I feel like fairly quickly we're going to see this evolve to requiring real identity for actual humans and ability to digitally sign content in ways bots can't replicate. That will then be the real problem outcome because the downstream effects of that will enable all kinds of censorship and control that we have thus far resisted / avoided on the internet.

This one really concerns me, especially for smaller, free speech communities like Saidit. You think the spam and disruption is bad now, get a couple of competent AI posters and you could completely derail a community.

An adversary would no longer have to pay for trolls and shills, just send in your AI army which never tires. It really seems like the next logical step in propaganda and silencing dissent, a la COINTELPRO and my frequently posted The Gentleperson's Guide To Forum Spies.

Frankly, I don't know how we combat this but any ideas are welcome.