Most games are simulations of real-life experiences; glamorous and exciting fantasies of activities that are denied to us in real-life, whether that be running an NFL franchise or blowing off some dude's head.
Now, new experiences are now being offered that force us to consider what is appropriate or otherwise as interactive experiences, even for adults. We can mostly agree that it is okay for Niko Bellic to mow down some innocent, or shoot a cop, or murder a rival. These are all vile crimes that we accept as entertainment for adults. But very few of us believe it is okay for a character to take on the role of that most disgusting criminal, the rapist.