It's difficult right now because they are mostly manual or semi-automated.
Tribes can choose to mute the bad actors. Depending on the mute setting, the user may or may not earn any tokens. However, I heard from Marky that it isn't reliable as we are seeing some fish that got through the net.
In the screenshot above, many abusers have chosen to upvote their own comments to reduce risk of detection. It's not apparent on Steem token-based frontends due to their tiny SP, but stick out like a sore thumb on the tribal frontend.
It's kind funny really, these dickheads' behavior corresponds to the way they act before the tribes. Many were flagged by SFR or are on the Global Black List.
I saw a post from Marky about the blacklist encompassing at least some of the tribes, though PALNet (the biggest one) is not included.
Steem Blacklist Notifier 1.0.10 - Now supports STEMGeeks, SteemLeo, Creative Coin, Weedcash, and SplinterTalk
It will take some time to settle down, but with it being more centralised I know certain people have already been given the boot. Is that good or not? We shall see.