How old are these children?
When I was a kid, my dad would let me and my brother and sister watch all kinds of violent action movies. The earliest one that I remember well was "Commando", with Schwarzenegger. People die, people get shot, things blow up, Arnold breaks guys necks - he drops one guy off of a cliff. Maybe not THE most violent ever but nonetheless. 105 people die in that one. (I looked it up)
HOWEVER, he put up a big fit to my mother because the comedy movie "Airplane!" had about 5 seconds of female frontal nudity. He may as well have broken out some holy water for that one. My mom thought (rightfully) that he was so ridiculous for that backwards mindset - Violence is ok, but a bit of nudity was evil and horribly wrong. So we weren't allowed to watch it.
It was ok to watch The A-Team, where a thousand bullets go flying (but no one dies or even bleeds) and things get blown up (but the bad guy always survives unscathed because he jumps out of the boat in time). Gunfire galore, but with no consequence to show for it.
How responsible is that?
Those same people who fully supported (and still support) gratuitous violence will turn around and sick the wrath of the lord on any simple nudity.
Remember the big, overblown deal everyone made about Janet Jackson at the Superbowl halftime show, for the exposure of (gasp) a nipple. God save our children from the nipple but bring on the guns and fist fights.
That's how most of society wants to think. The same society that pushes alcohol at us in commercials, and pushes pill after pill at us as well, is completely intolerant about marijuana.
This is the world we live in.
Anyway, kids shouldn't be shielded from these things because they will find it eventually. It is better they see it with their mom or dad, who can explain things to them, such as reality and fiction, right and wrong. If they don't, then the kid sees it as some cool and mysterious thing because mom and dad are keeping them from it. You're not protecting them by hiding it. You're only making them less prepared and aware. Kind of like the sex talk (which I never got as well).