One of the big problems with harassment on a platform like Twitter, and this seems to be pretty hard to get across to people who haven't been subject to it -- or don't know someone who's been subject to it, at least -- is the speed and intensity of what's coming at you if a true pile-on happens, or if a particular group decides you are The Enemy. You can mute and block a handful of jerks and get on with your day, perhaps, but if everything you post is greeted with hundreds (or even thousands!) of responses along the lines of "we're going to dox you and I hope someone rapes you to death," we're talking about something very different than "people are being mean to me on the internet."

I'm not sure if all of Twitter's problems come from mere scale; it suffers from what analyst Ben Thompson has called the Pollyannaish Assumption: we focus on the upsides of the "global public square" without accurately evaluating the downsides, and bluntly, I see this a lot in discussions on HN. It's the subtext of "why can't people just block and move on." Arguably, focusing on the downsides without accurately evaluating the upsides, which I also increasingly see a lot on HN, isn't really an improvement -- but if we're going to have platforms like Twitter and Facebook, the question of "what do you do about harassment, hate speech, and stochastic terrorism on those platforms" needs a better answer than "suck it up, buttercup."