10. The Nazis or Hitler
It had been done, but it really shouldn't have. Nazis and Hitler, even though a big part of world history, really should have no part in a science fiction show made for children and families. Let me be more clear. Doctor Who has always been children friendly, although some may disagree that it's made for children. It's not specifically for children alone, but it was always suitable for them to watch. The Nazi period was a violent, hostile point in time and Doctor Who has until recently stayed away from topics such as this one. At least the television series has anyway. It may be an interesting subject for some, but for others they cringe because it's a very touchy subject, and could offend viewers. I agree that it is a subject people should know about, but when it comes to a show people want to sit down and relax to, this topic would definitely not be one of those.