I was thinking of replying to a question posted in another thread, and it prompted me to wonder, when does a game cross the line?

In my case, Quake 4 did it with the cyborg babies, which was just too much for me to handle. The operation where "my" legs were removed was bad enough, and I almost stopped playing there.

Postal was played briefly but it took bad taste so far that it was satirical. It got quickly deleted.

Battlefield Vietnam was fun, but I stopped playing it as I realised that the generation before mine had, at my age, fought in the war being played out on my screen.

The same goes for the Grand Theft Auto series, which are satirical fun, but eventually my conscience suggests that perhaps beating up prostitutes is not the best use of my leisure time, and I switch to something else.

So I'm asking, when does a game cross the line, and why?