Godwin's Law was first identified on the internet (USENET to be specific), but comparisons with nazism comes up in real world conversation and debate as well. The memory of fascism, and what it did to humanity, is constantly references in science fiction, discussions of psychology and theology, and, of course, in our political life.
There is a reason for this. While Godwin's law was formulated as a comment on the knee jerk reaction people had to nazism, and the fact that nazism can be associated with anything; it is not at all silly to have a knee jerk reaction to nazism, or to associate many things with nazism.
What happened in Germany (as well as what happened in Japan, and to a lesser degree in Spain and Italy), was the most significant event to happen to humanity last century, and it impacted every aspect of our world culture. To bring up, say, gun control in reference to nazism is not at all silly or off-topic. The question of whether people need assault rifles to fight off another age of fascism is not an irrelevant question. It is an incredibly relevant question. When people propose an educational movement that encourages orderly behavior among students, the question of what the consequences are of teaching youth to automatically follow authority is not at all alarmist. While writing this, and trying to imagine some hypothetical examples to illustrate my point, Cardinal Joseph Ratzinger was elevated to the position of Pope Benedict XVI. In his early youth, as all Germans were, the new pople was a member of the Hitler Youth. Participation was mandatory, and there is no evidence that he ever agreed with the nazi cause, but we still have a Pope who was a member of the nazi organization. This is not a trivial matter, and mentioning it is not just a smear.
The problem with arguments like these, and why we still need some form of Godwin's rule, is that people often use nazism to stop discussion. As Thedore Adorno pointed out, the enormity of nazism was so great that its mention stops discussion. Given the horror of their crimes, it seems almost disrespectful to defend someone or something once it has been linked to nazism. The problem is, not every feature of nazism was outright evil. The nazis had many negative features: they were racist, militaristic, brutal, autocratic and corrupt, to name just a few. However, there have been many governments and organizations that have been racist and violent, without sharing in the radical evil that nazism represents. I do believe that nazism represents an evil beyond just their common badness. However, the evil stains even the trivial things that characterized the nazis. Liberal critics, for example, may point out that The Boy Scouts are a semi-militaristic organization encouraging group conformity, much like the Hitler Youth. Whatever the minor similiarities are true, the insinuated connection is that the Boy Scouts also share in the evil of the Hitler Youth. Whatever their faults, the Boy Scouts don't indoctrinate blind obedience to a genocidal madman as part of their code of conduct. To give an example on the other side, it could be argued that many pagan and neo-pagan groups share a religion or belief system with the hodgepodge of mystical beliefs that certain parts of the nazi party espoused. Whatever the downsides of paganism, even paganism that is focused on Nordic traditions that may be racist, the mainstream of paganism does not condone genocide. Thus, Godwin's Rule is neccesary because "accidental" features that groups share with nazism are associated with the the essential feature of nazism, which is pure evil.
So then, the mention of nazism is often very appropriate
in discussions of many different types, however, Godwin's Rule must still be remembered because of people trying to end discussions by painting people or organizations with the nazi brush.