that is not "trolling", that's (pretty bad) harassment. I get the feeling this is a story written to prove a point. Nobody would refer to this as "trolling".
How would you define trolling and a troll? I'm sincerely asking since it is my understanding that these days harassment over the internet is often cited as trolling, as in for example "We trolled Jane by spamming her inbox full of animal abuse and violence lol". I work part-time at a school with kids ranging from 7 to 16, and of what I've tried to inquire them about the subject(I'm 22 myself, so it's quite easy to go…
The problem with calling it all "trolling" is that it normalizes the seriously nasty things (e.g. threatening to kill someone's wife) by analogy to the less serious things ("I tease my friends all the time").
At some point, these are very different things. And they need to be treated very differently. Calling them different things (e.g. "harassment" or "hate speech" vs "trolling") helps set up that mental boundary in peoples' minds and helps them demarcate what's right and wrong.