There was a dossier given to the police detailing what you say were 'the same sort of hateful online activities to which the McCanns were subjected'. The police and the CPS found those activities were not worthy of prosecution, so they must have been different. I assume the McCanns were aware of the dossier if it was their family who handed it over.(as Hogan-Howe suggested). Ergo no-one has 'tormented the McCanns in the way Spivey did the Rigbys', or they would have been arrested too.
The dossier was compiled and handed to the police by McCann family
supporters, not by the McCanns themselves - read the news reports of the time. BHH was wrong, obviously. Having been an observer myself of some of the online activities against the McCanns over the years I can state hand on heart that these differ in no substantive way to the activities of Spivey. There really is little or no difference, so either the police are not being even-handed in the way they go after trolls and online hate-merchants, or they are powerless to act unless the complaint comes directly from those suffering the abuse themselves. It is my belief that the latter is the most likely reason why some of the worst McCann "sceptics" have not been dealt with in the same way as Spivey. Perhaps if and when the McCanns get closure on their daughter's disappearance it will be time to go after these people cos they sure as hell ain't going to stop their tormenting any time soon.