European here.
I think Fpqxz is right. We are not as big on free speech as you Americans are. Your free speech is probably the most important thing in your community, your system is built upon it. We are less for letting everyone speak their mind, and more for protecting the people. An example :
Basic Law for the Federal Republic of Germany, art.1, pas.1 :
„Die Würde des Menschen ist unantastbar. Sie zu achten und zu schützen ist Verpflichtung aller staatlichen Gewalt.“
Rough translation : "A humans dignity is untouchable. The government is obligated to respect and protect it."
Therefore, if something goes against the dignity of a human, it can be stopped. Hatespeech is outlawed here in Germany. While there are obvious drawbacks, there are also positive points. No Westboro Baptist Church, for example.
That doesn't mean that the government controls everything we say. Most of the time it's cautious with that, because of that whole Hitler thing. But the Holocaust is an exception.
As long as I can remember, I've been told what horrible crimes against humanity have transpired during the reign of Hitler and that we should do everything possible to stop it from happening again. During my schooltime we got different sources from that time, and we visited the concentration camp in Neuengamme. I also talked with my grandmother, who grew up during that time. Her whole life she said that she didn't know about the Holocaust, but when she was very ill and we thought she would die, she told me that the people had a very good picture of what was happening, but the media just said that the Jews were evil. And as she said : If you are told something for a long time by almost everyone, you start to believe it.
So, you may ask yourself what I want to say with this incoherent babble, so let me summarize it : I've been growing up learning of the horrible things that can grow from hate. Therefore, for me, protecting dignity is more important that absolute free speech. Therefore I'm in favor of laws against Holocaust denial.