I'm not a professional game designer, but if I ever end up becoming one I would be extremely insulted if this is what people used my game for, and thus I wouldn't give them that option, but that's just me.
I'm sorry to give you the wake-up call, but people desperate enough will ALWAYS find a way.
Rule #34 is always applicable. Always.
You cannot dictate what people do with your game.
You can only make sure it's as enjoyable as possible, and truly represents the vision you had when you started it's development.
Extremely insulted? Why? There are always a sad and poor few that end up using a game to vent that way. But they don't shove it into people's faces, they don't bother anyone with it, so as game developer, you wouldn't even know that "it" happened. Why even worry about that?
I'd much rather feel honoured and happy due to 99% of my customers, which immensely enjoy the game the way it's meant to be played. Yes, the creator of Bioshock Infinite was offended to find porn of his female lead character on the net. I'm sorry, but you're releasing a game into the wild, rugged and perverted lands of the internet. If you didn't see that coming, you need to do a reality check.
Be glad about happy customers, and just don't think about what sad people might use your game for. It's going to happen, and you can't prevent that, not even by not putting any nudity in your game.
That being said, I agree with all of Tony's latest posts, and can't really add anything else.
Also getting tired of the topic, as it's entirely up to the devs, and they don't seem to be interested in discussing this, which is fine.