If you read up on the Kiwifarms Wikipedia page [0] it sounds like someone needs to go to jail. Until this moment I'd never believed that sending someone a pizza would qualify as an act of violence - but now I can see it. If the site doesn't break laws then there is no reason to ban it. But there are criminals using that site and they should be caught. Banning the site is just dodging the real problem.
[0] https://en.wikipedia.org/wiki/Kiwi_Farms