> This is such a terrible idea. All this accomplishes is causing extremists to find echo chambers where they will never actually know what they're doing is wrong. It's much better to keep extremists in mainstream platforms so they can be called out and atleast informed that they are wrong. Your solution is totally backwards and accomplishes the opposite of what you're hoping for.
It's not that simple:
1. It's totally believable that someone might follow a neo-Nazi on twitter, if the neo-Nazi avoids Nazi iconography and mainly tweets about Nazi-adjacent topics, but have second thoughts about joining an actual neo-Nazi website.
Not all extremists will seek out a fringe echo chamber. Some will, but others will not. The result is likely one where the most-extreme core gets separated from its recruitment opportunities, disrupting the first step in the recruitment funnel. That core may get more extreme in its echo chamber, but its overall movement could end up being smaller and weaker.
2. Counterintuitively, people tend to dig in to their existing beliefs when they're "called out." Also, I'm sure every neo-Nazi has been informed many, many times that they're wrong. Extremism is not a problem of lack of information.