Manhunt 2 isn't on this list. The logic behind banning that murderfest makes sense.
There has never been any hard proof that violent video games can cause antisocial behaviour. Lack of evidence hasn't stopped people from claiming the release of overly violent or sexual material leads to a degraded society.
It's called a social panic. The media loves a good social panic and so do developers, because nothing sells like controversy.
Whether or not you believe that controversial material can have an effect on people (remember there's no hard proof), it's worth playing devil's advocate when material gets banned. When you do, you can sometimes see the logic behind removing something for general consumption.
Sometimes though, the ban makes no sense.
The following don't follow a simple pattern of motives. Occasionally there is a wider political reason for a ban and at times the context behind the prohibition is not sound.
We all have different lines on what we deem acceptable. No one item or argument is likely to change your views. But you can at least agree that there is a lack of sense in the reasons for outlawing the following.