In the hierarchy of censorship-worthy images, Facebook's priorities seem askew. The global social media site decrees that photos depicting breastfeeding babies are subject to removal if the mother's nipple is visible. But, thanks to a policy change announced Monday, videos of beheadings and other physical mayhem are perfectly allowable as long as they are not presented as overt celebrations of those acts.

Free speech, the concept that most distinguishes free societies from captive ones, can be hard to define and harder to judiciously regulate. Where do we draw the line?

The short answer is, we can't. Context is everything -- and context is in the eye of the beholder. Breastfeeding's nutritional and emotional benefits are undeniable and well-documented but direct-from-mother nutrition still isn't sufficiently practiced or accepted. As a result, breastfeeding remains somewhat stigmatized, limiting the number of mothers who might otherwise be inclined to do it -- and perpetuating a society that's not as healthy as it might be. Facebook understandably has no interest in crossing the line into soft porn, but at some point we all have to agree that promoting breastfeeding benefits society immeasurably more than leaving the door ajar to pubescent ogling harms it.

The same is not necessarily true of decapitation videos. While some may legitimately use shockingly violent images as a way to protest and draw attention to those archaically gruesome practices, it's not clear that the potential good of those protests outweighs the potential harm those images might do to immature or troubled minds.

Does that mean that, unlike breastfeeding, beheading should be banned from Facebook and its 1.5 billion users? That's a tough call. It won't break our hearts if Facebook reverses itself again and bans the guillotine. Remember, Facebook is a private entity that has the right to pretty much establish its own restrictions.

But in a free society we accept the fact that depictions of men's darker nature will always exist, somewhere. It's the price we pay for remaining free of forced conformity -- political, economic, cultural -- that authorities might try to thrust on us. So, where do we draw the line? We don't. We simply accept that it's a question we will be asking ourselves in perpetuity.