I'd like to address some of the claims you are making.

First of all, you are defending a law that abridges free speech in Austria and Germany. I must say this surprises me: I never thought I would meet anyone on Hacker News being for the abridgment of discussions. It seems ironic, at least.

Second, when you say 'holocaust denial' cannot be put in the same class as 'anti-government messages', I would defend that is wrong on its face. After all, the law being discussed exists in Austria and Germany for a reason. Also, if you read the work of Norman Finkelstein, jewish writer, he would most forcefully disagree with you, with several examples of the US and Israel using the holocaust as a political tool; so I recommend you read him in order to refresh your arguments.

Third of all, you suggest that David Irving is some sort of a lesser historian. I want to let you know that Christopher Hitchens defended him strongly during the time his case against Lipstadt was going on, and he successfully argued during a Charlie Rose show that David Irving was an established, serious historian. You may say that he used known fabricated documents as a source, but you did not source that claim, and I challenge you to do so. Instead, Hitchens argued we should be on Irving's side because Lipstadt broke the contract by backing away from the publishing deal.

Fourth, there are other cases you haven't mentioned. Germar Rudolph I believe was also arrested, or at least otherwise banished from academia. There was also the case of Sylvia Stolz who was a lawyer who was imprisoned while defending her client. I would be interested in your interpretation of the events that transpired on those cases.

Fifth, if you believe that Ernst Zundel was justifiably arrested under 'hate speech laws', I would recommend that you brush up on counter arguments to that by Walter Block, jewish philosopher, who successfully argues against anyt sort of slander and libel laws, which would encompass hate speech under his views. I say 'successfully argues' because his debate opponents have never presented a counter-argument he could not refute.

Sixth, you say the laws only stop people from playing politics with the holocaust and not from researching it. This is the inverse of what happens in reality, and again I refer you to Norman Finkelstein. The laws being in place enable the exploitation of the holocaust by politically motivated U.S. and Israel. Finkelstein enumerates several examples even on his interviews so you needn't buy his book, though highly recommended. The laws being in place are what stopped Germar Rudolph from continuing his research. Unless you have an example to illustrate your view, it seems you are equivocated here.

And finally, when you say the scale of the holocaust was large, and that there was a heap of physical evidence, you never specify which evidence you are talking about. This is important because, as with any ongoing research, what was deemed evidence once may now be recognized as fabrication, which is what happened with, among other examples, the claims that jews were turned into lampshades, the claims that soap was made from them, the claims that the method of killing existed in Germany, the claims that the methods of killing were operated by pedaling-power, or that their floors would open and close, etc. Those are all deemed fabrications by modern historians, and they once were presented as "evidence". Would you please list the evidence you allude to? As for eyewitnesses, how do you square the disparity between Sondercommando's account of their deeds and their description of the bodies turning blue (reported by Dario Gabbai and other Sondercommandos as described in Jean-Claude Pressac's book) and the scientific knowledge that the bodies turn red when submitted to those procedures?