I don't see this as suppressing dumb ideas. Quite the opposite -- it's fueling a national debate about those ideas. These people are getting much more of a platform than they'd otherwise have, and I disagree that it gives them credibility. It gives them warranted (and necessary) visibility, juxtaposed against a social backlash, which hurts their credibility.

To your second point: what makes you think doxxing them is going to motivate them to victimize people that they wouldn't otherwise victimize?