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.