You can't censor it away completely, but you can help the redeemable extremists __know__ they're indulging in extremism by forcing them to go to fringe websites rather than allow them to stay on Twitter and Facebook as if nothing is wrong. As for the "deplorables" who know what they're doing and will never question it or feel any remorse, we should not be giving them a megaphone.
sources[0]: I was susceptible to extremist thought (not actions, fortunately) when I was younger. The sense that I might get into trouble if I participated in fringe websites kept me from going further down the rabbit hole. I kept reading mainstream news and sites, and while I would give a lot of things an extremist spin in my mind, eventually the narrative stopped making sense.
sources[1]: https://twitter.com/iyad_elbaghdadi (can't find the specific Tweet, but he went through a similar experience, and almost became a full-blown extremist Muslim, before the sites he used to frequent were taken offline).
sources[0]: I was susceptible to extremist thought (not actions, fortunately) when I was younger. The sense that I might get into trouble if I participated in fringe websites kept me from going further down the rabbit hole. I kept reading mainstream news and sites, and while I would give a lot of things an extremist spin in my mind, eventually the narrative stopped making sense.
sources[1]: https://twitter.com/iyad_elbaghdadi (can't find the specific Tweet, but he went through a similar experience, and almost became a full-blown extremist Muslim, before the sites he used to frequent were taken offline).