william: j.m. bergern you pick up on the point cynthia is making he? help us undersnd how social media and internet communities help a radicalize draw a new adherence to these movements. >> what we see on these networks is diverse a so the very different dynamics. represented was qanon. that group has a centerit of grthat is heavily online. that's a very large movemen that has really proliferated in the social media space. soe can put a lot of blame for pthem and thesence there on social media. other groups existed in previous forms. certainly we he had neo-nazis, confederate milit movements that have existed long before social media, but nowin they are social media to organize, to recruit to some extent, and to get each other pumped up for an activity like thi and increase the sense of urgency and crisis they can take extreme action. william: help us understand, we have seen some soal media atforms have tried to crack after wednesday's event. we know this is a cotion one for the lot -- a lot of platforms

it's a topic researcher j.m. berger for years. >> it was clear then, and all the research i've done since then is clear that when you deplatform people they lose audience. >> reporter: berger's 2015 study of hundreds of isis twitter accounts showed that hashtag isis was mentioned 40,000 times a day when twitter began suspending people in september 2014, dropping to only 5,000 mentions a few months later. berger and morton concluded that social media suspensions work best when they're consistent, fair, and rare. unlike jihadis, right-wing supporters are legion, include multiple different ideologies, and can count on some elected officials to defend them. >> you should be able to sue -- >> when you're taking down accounts of muslims, people didn't really care. when you're taking down, you know, the accounts of prominent people, people are going to care. and the platforms are very aware of that dynamic. >> and you know, we've already started to see, brian, some of this play out in the same way with election misinformation.

and j.m. berger, the author of several books, including "extremism." he has conducted research and traing on issues related to homegrown terrorism, online extremism and how to counter it. thank you both very much for being here. jm berger, to you first. you were-- help us understand how large a presence we know that these extremist groups were at the rally on wednesday. meaning if you could show hav taken them off the chess board, i don't mean arrest them, but i mean magically remove them from the circumstances, would wednesday ve been a different day? >> i think that if you removed the extremist groups from the circumstan, what you would have seen is what direct threats to the member of congresses who were present there, and to vse president pence, there may still have been the rush on thel. capi there may still have been a riot. but what we saw was people in come bat gear carrying zip ties who clearly had the intent to do something more than just riot. so that was really a close call and close call we could have avoided if the extremists hadn't been