Trolls and abusers have been in existence since man (or woman) were scratching on cave walls with bits of flint.
Online abuse is ubiquitous and precedes the McCann's by a decade on line - PowWow, ICQ, and AOL Instant Messenger were overrun with imbeciles posting any old sh**e to whomever they chose, as it was largely unmoderated, as were most other platforms.
You see it as a focussed campaign because you're focussing on it - Joey Essex probably gets more intense online abuse, you just don't have an interest in it.
I think there is a slight difference in that the McCanns (collectively ) have suffered a terrible tragedy (unlike Joey Essex as far as I know) and the attacks on them IMO serve only to heap more cruelty onto individuals who have suffered the cruellest misfortune. Now, obviously if you believe they are murderers or evil liars then that gives you some justification for your sport, but it still really doesn’t reflect very well on those doing the abusing IMO, and I’d include everyone who is STILL banging on about the neglect issue 12 years later. We hear you, we heard you 12 years ago, it may make you feel good about yourselves to harp on continually about it, bit at the end of the day it achieves precisely f-all.