I think what the internet and social media allows is for them to form groups, become organized, and be collectively influenced by agitators to take action.
Comic book guy used to just sit in his room geeking out over comics. Maybe he was friends with a couple other comic book nerds. They might be like, "Damn, I wish I could get laid." But that's where it kind of stopped.
Now you have large pods of comic book guys coalescing into groups online. Those groups have overlap. And as the people in these online communities get to talking, they start to wonder wtf they aren't all getting Batman level's of pussy. It becomes an echo chamber of sexual disenfranchisement. At that point, they are ripe for conversion from being a support group of sexually frustrated geeks to being a motivated force for taking action and striking out against their perceived nemesis. It just takes the right messaging and view of events to set them off.
That's a pattern happening with conspiracy theorists, racists, incels, anti-vaxxers, environmentalists, BLM, #metoo and other groups. Some of them are righteous causes that have been corrupted or coopted, either wholly or in specific instances. Collectively, its all leading to a growing sense of societal malaise and erosion of faith in our institutions and each other. Its a problem that no one is effectively combatting, maybe not even trying. Efforts seem more focused on adding groups of angry, scared and motivated followers to your political tribe.