he really was radicalized in these digital spaces. >> williams: balliet spent time on message boards shootings, with advice on how to carry them out and tutorials for making weapons. >> we often see these shooters as lone-wolf, single people carrying out these attacks. but if you look at the communities they spent their time in, you can clearly see that a lot of people work together on this. they crowdsource ideas on what targets are the best targets, and what weapons should you use, what materials to create bombs. and i think that's also the reason why he streamed his attack in english, because there's this global community. (device chirping) >> williams: balliet's live-streamed video ultimately attracted more than 2,000 viewers. many posted supportive comments. >> there's a huge community of these people. and it's an international discourse that's happening that's driven by people from the united states. but a lot of other people from the worlare part of this discourse. and i've seen a huge interest from germans. and even if the group's only 80 people strong, at least five people o