vote manipulation is going to be a problem for federated communities

I guess, but since the feed isn't algorithmically created to maximize engagement (the tools are better than commercially driven sites) I don't think it matters as much. I think of it as a "Who's Line Is It Anyway" condition - everything is made up and the points don't matter. And, tbh, I really like that I can click into a stupid-x story without worrying that I'll be fed stupid-x content for the next week. It's worth a little vote tomfoolery, imho.