Well on more anonymous platforms like HN or Reddit it probably doesn't happen that much, but on youtube, instagram, twitter, etc usually identity is no secret.

This is just more of my opinion, but generally the people I know that get caught up in bad echo chambers would have done so without the internet. The Alex Jones fans are just a new iteration of Rush Limbaugh fans, albeit more extreme. I think it's possible for otherwise reasonable people to get caught up in something like that, but they can also get out with time and more life experience.