I _can_ comment on all the other statements cited on that page. But others already did, so why should I repeat more of the same?
"This is [harassment]" meant all of it, incl. the one I referred to (and a bunch of others that may be angry disagreement, but are not violent, and not necessarily harassment). Comes to show that the definition of harassment isn't as easy as "here's a list".
Since you asked so nicely, to give you a comment on all those other posts, let me stick to those who are unquestionably harassment - those containing threats of violence and death (I just don't feel like arguing about a more precise definition with a random internet stranger right now):
It's kind of amazing how limited the vocabulary and breadth is in those statements. It's essentially the same 4 or 5 insults and threats reiterated again and again and again, with the most variability in the order of words - any resemblance of grammar is obviously optional in the first place.
So when I first saw that collection (a couple of days ago, so I'm not rage-struck anymore - maybe that explains why I'm not joining the chorus), I was considering if some trolls created tons of throwaway accounts and dug deeper - those are accounts that are primarily used for other purposes, with a wide range of profiles: old accounts, new accounts, students, adults across all professions (as per their bio). All of them with "normal" posts before the one listed there, and after.
So trolls creating throw away accounts are out. Since the accounts are still in regular use, it also doesn't look like a massive take over.
So there are really two options:
1. these accounts are taken over in some non-intrusive way by aggressors (eg. cross site scripting, reuse of simple to guess password)
2. people across the board (all ages, all professions, all sexes and genders) share such an annoying conduct[0], and it's likely that in your/my/anyone's neighbourhood there are a couple of such people otherwise living normal lives.
So, people are monsters, and there's no clear marker to pinpoint them except their conduct.
What else is new?
[0] I do assume that except two or three deranged people, they leave it at verbal threats like these - which doesn't mean that this is okay, individually or collectively.
Besides showing some crass personal flaws, it's just as frightening for the target since they can't know what's real and what's "for show". There's also a real risk that the truly deranged feel encouraged by so many people who seem to be alike on the surface.