It’s absolutely true that every community has these types of people in it. And it’s a shame that they’ve become such a force on social media. It’s one of the biggest downsides to the internet; the online world is an awesome place for people to share ideas, have constructive debates/dialogues, and maybe even engage in a little activism while they’re at it. But it’s not so awesome for the people who end up on the wrong end of an online witch hunt, especially when it gets to the level you mentioned (doxxing).