Yeah it's wrong to hack someone's account...
...but part of me can't help but think that anything that makes the life of this grubby little fascist (he described himself as such) a bit harder can't be bad. Irving has made a nice little income from Holocaust denial.
As for free speech, that really is a tough one. After all Irving has variously claimed that Hitler knew nothing about the Holocaust, that the Allies faked the story, that there were no gas chambers, that there was no organised extermination and so on and on... His stories have been disproven in academic journals, books, papers, even in court and yet he still rattles round the far-right circuit spilling his venom. I can't begin to imagine how much distress he causes to survivors and relatives of the dead. But yes, he should be allowed to speak - and as soon as he steps over the line, then he should be dragged in front of a court and bankrupted all over again.
One thing that's easy to do would be to stop calling him a historian. Court judgements say he has faked and exaggerated his evidence. So perhaps the next time he turns up in print or on television they can just call him 'David Irving: Nazi fantasist'?