I'm pretty sure Germany's had laws about denial of the holocaust since well before modern internet culture was around.
Sure, but that didn't cause much conflict with other cultures. German laws only applied to Germany. But with the Internet, it is common to find forums that mingle people from different cultures, and different legal jurisdictions. One of the big differences between cultures, is how they deal with the tradeoff between "freedom" and "order". Americans and Germans see that tradeoff from very different historical perspectives, and make very different tradeoffs. As an American, I believe that people should be able to express even the most odious opinions, and suppression of those opinions causes more problems than it solves. The Germans see it differently.
... then they came for the Nazis, and I did not speak out because I was not a Nazi.