(Daniel Acker/Bloomberg via Getty Images)

Facebook will now let users upload graphic videos of murder, as long as the intent is to condemn the violence, but videos of nudity are still mostly verboten.

The social networking site, which anyone over age 13 can sign up for, put a temporary ban on graphic images and videos in May after concerns that videos of beheadings could cause users long-term psychological damage. The ban was quietly lifted this summer, with the caveat that the intent must be to raise awareness and condemn the violence rather than condone it.

"Facebook has long been a place where people turn to share their experiences, particularly when they're connected to controversial events on the ground, such as human rights abuses, acts of terrorism and other violent events," Facebook spokesman Matt Steinfeld said today.

"People share videos of these events on Facebook to condemn them. If they were being celebrated, or the actions in them encouraged, our approach would be different," Steinfeld said, noting that when Facebook reviews the videos that have been reported as graphic, they look at the context in which it's being presented.

"We want to draw a distinction between users who want to share events that are important to them and videos that are being celebrated and shared for sadistic pleasure," he said.

The networking site is currently testing disclaimers for graphic videos. "There are a couple graphic videos out there that have screens on the front end that say what they're about to see contains graphic content - but it's not on every single one," Steinfeld said. "We're seeing how scalable it is."

If implemented, the disclaimer would be for any user, not to any specific age group. "But that's also one of many things we're trying to figure out right now," he said.

On its website, Facebook says it imposes "limitations on the display of nudity. We aspire to respect people's right to share content of personal importance, whether those are photos of a sculpture like Michelangelo's David or family photos of a child breastfeeding."

It also prohibits content that resembles hate speech, spamming, or bullying.

Facebook quietly changed its policy this summer on the kinds of videos users would be allowed to upload to the social networking site.

Critics questioned Facebook's video policy on violence.

"The idea that anyone, let alone a small child, could actually see footage of a beheading is the worst idea I've heard all year," said Mark Potok, senior fellow at the Southern Poverty Law Center. "Facebook won't allow the world to see a naked female breast but apparently they're happy to show people's heads sawed off with knives. I don't think seeing someone's head sawed off with a knife is educational - it's just incredibly bad taste."

British Prime Minister David Cameron Tweeted that "It's irresponsible of Facebook to post beheading videos, especially without a warning. They must explain their actions to worried parents."