Do you want me to spend some time counting them all up and putting up some research on the subject? Would you accept my findings if it showed (as I suspect) that abusive tweets about the McCanns outnumbered abusive tweets to the others you mention by a factor of at least 10? TBH I'm less interested in the anguish caused to the McCanns and their family by these tweets (surely they must be hardened to the idea that thousands of people utterly despise them?) than in the motivations of those who feel the need to be so vile on a regular basis. Why do they do it? What pleasure do they gain from it? They pretend it's because they want "Justice 4 Maddie" but IMO that's rubbish, a convenient smokescreen to excuse their vileness. They just enjoy being horrible on a regular basis and the McCanns are their chosen victims.
So as the Mccann's claim not to use social media, they won't see these tweets.
How would you stop these tweets from both extremes ?
Likewise, I have seen 'material' , for want of a better term, on forums from both sides, classifiable as a noxious.
Bottom line, most people don't indulge in this behaviour.
I do find it hypocritical that you expect the Mccann's to come under no criticism at all for their actions, yet you criticize Amaral and the PJ, at the time he was team coordinator.
In the end, it is where people draw the line, and some people don't know when to do that, as we see on Twitter and other social media.
One thing I have seen over the years in my profession, people can always live down to your worse expectations.