I have written about on-line 'trolls' (as they are known) on previous occasions, and my attitude toward them is well known.
Although I have never experienced anything like what Leo Traynor has recently been put through by one such, it is only a matter of degree between any one such troll and any other: if someone has that attitude that underlies all such behaviour, then that can be thought of as a 'Minority Report' kind of situation.
Just because it hasn't yet escalated into the more extreme realms is no reason to believe it won't – and I have observed several on-line trolls ramping up their boldness and becoming more nasty, even bordering on an indirect form of threatening style over a period of time.
Do read Leo's post: although in this case it turned out to be someone he already knew (and I wonder whether that is something that's more common in this business than is yet known?) the point remains that no matter who it is, there is no excuse for trolling at any level, aimed at anyone.