When it comes to the various hate mail that Madeleine's parents received I am rather reluctant to see it as being the actions of one particular 'side' and therefore expect that sought of behavior from them all. These people who feel the need to impose themselves on a family's grief and misery do so for selfish reasons and in the hope that what they send will in some way destroy their resolve. These people have always existed and always will. They have latched onto this case to make it about them, how they feel, how they are offended and angry that the McCanns have according to them, escaped justice.
But these people are a minority I believe, and certainly do not in my mind represent all of those people who have a differing theory as to what happened that night back in May 2007.
Anyone who has followed the case from the early days will know as well as anyone just how twisted certain people became and behaved regardless of their beliefs. The only thing they had in common was how they chose to manifest this which was always abusive and making it very personal beyond merely debate on the internet.