Damnatio memoriae is devastating to a public figure, but it is doing KiwiFarms a huge favor. It lets them scurry away under some new rock and keep going under a new name. The worst thing you could do is probably just shine the brightest spotlight you can find square at their activities.
There is a good reason we erect monuments and museums to atrocities. It's not for ease of rubbernecking, but so that we can learn and avoid them in the future.
Although it does enhance my point, which is that Kiwi Farms benefits from this.
If you try to convince them, likely you would get an unbelievable amount of negative online attention sent your way. Ironically the same thing they hate Kiwifarms for.
In practice: The abstract entity KiwiFarms takes all the shit, very few of the people actually constituting its membership seem to take much flak; meanwhile its critics look completely unhinged, even though they're absolutely right and KF is incredibly reprehensible, they still do their best to undermine the credibility of their own cause by acting and behaving like a frothing at the mouth lynch mob much more interested in power-tripping and revenge than truth and justice.
The strategy is straight out of Sun Tzu on how to deal with a stronger army, and I haven't really seen any examples of anyone handling it well.