Earlier quoted context omitted.
You've probably thought of this, but if you can associate votes to identities then a classic way to mitigate this behaviour is quadratic weighting, where e.g. your nth vote costs n^2, so a censor or propagandist needs to pay 1e4 counteract the single votes of 100 casual observers.
Yeah, quadratic voting is one of the potential solutions to this, but ultimately that removes the ‘fraud load’ by mostly moving it to another place, to number of accounts. That is arguably worse because it incentivises the malicious users to create as many accounts as there are votes so as to not be subject to quadratic voting (1 vote = 1 energy point equivalency only holding at one vote), and it’s substantially hard…
What about:
weighting a vote by the "degree of separation" of the voter? (ie., friends count more)
hyperbolic discounting of karma acquisition
limiting the number of voters per item
new accounts can't vote until achived a network & karam status (eg., shares, by friends, are upvoted).
accounts which primarily upvote/downvote outside of their network are ignored
etc.
I think this adds up to saying, "small networks of voters" are the primary type of community; and big-network effects are largely discounted. Where things are popular, they are because many different active communities appreciate them.