This one has been getting a lot of air time in the US lately. Basically, what it says is that Darwin's theory of evolution (they tend to call it 'Darwinism') was used by Hitler to justify the Holocaust, and therefore evolution is evil and should be rejected. This particular argument has the usual logical flaws & also shows a lack of knowledge of history, to boot.
What don't I like about that argument?
Well, aside from the use of 'Darwinism' to mean 'evolution' (quite possibly to imply that science hasn't moved on since Darwin's time) – did Hitler really invoke Darwin? The answer has to be no (read the comments to this thread) – but he did use the germ theory of disease as a metaphor for what he saw as threats to Germany, and the need to sterilise the nation. Yet Koch and Pasteur (both responsible for significant discoveries in microbiology) aren't held up as bad people because their ideas were used in this way.
And in any case, even if Hitler & others like him did invoke evolution to justify their evil, this does not invalidate the theory and fact of evolution. Charles Darwin recognised that natural selection is the agent that kills some members of a population (or prevents them from breeding), and thus shapes the population's gene pool over time. This recognition of the power of the environment to drive heritable population change remains in force – regardless of the use to which it may be put.