I find myself far more in agreement with Salman Rushdie than with Elie Wiesel. Rushdie points out that laws against Holocaust denial turn evil little racist twits into free speech martyrs and allows the most vile and despicable of morons to wrap themselves in the mantle of free speech.
Personally, I say: Let them have their free speech. Then bury them with refutations and ridicule.
A while back I had a parallel discussion about the banning of Mein Kampf. A friend of mine was of the opinion that censoring the book would do nothing but good. Aren't there some ideas that simply don't deserve to be circulated, because of the danger they pose? Aren't some things best left alone?
I said no, because:
Banning something turns it into contraband; it only makes it all the more interesting. Putting Mein Kampf into a modern-day Index Librorum Prohibitorum would only fire that much more curiosity about it, and go that much more towards legitimizing it as a object of persecution. (If it pisses off the Powers That Be, it must be doing something right!)
The same goes for people who rally around it. Banning the text gives them that much more of an opportunity to wrap themselves in martyrdom. Leaving the book freely accessible makes them seem less courageous, and more commonplace.
You cannot win an argument with someone by kicking them out of the room If Mein Kampf is so indefensible, then document its indefensibility for all to see.
There's more points, but those are the most crucial ones. I'd formed my feelings on the subject back when I had first been introduced to Holocaust denial as something a bit more than just an abstract issue of debate, and saw that while you can't change the minds of the worst offenders, that's not the point: it's to document for others, both now and in the future, why their arguments are worthless.
Free speech is something where you have to give as good as you get, and the way to get the best out of it is to use it to refute it at its worst.