ALLOWING grisly decapitation videos on Facebook may actually help reduce violence, a leading Australian academic says. The social networking giant confirmed it has lifted a temporary ban on the graphic clips and other potentially shocking videos and images, saying it wants users to condemn the content, not encourage 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," a Facebook Australia spokesman told AAP. Facebook, which has nine million daily users in Australia, banned extreme graphic content in May after the Family Online Safety Institute - a member of its Safety Advisory Board - complained that decapitation clips "crossed a line." That ban is now lifted, though Facebook, which allows children as young as 13 to join, will consider posting warnings about graphic content. Dr Suelette Dreyfus, research fellow at University of Melbourne's Department Computing and Information Systems, characterised Facebook's decision as a victory for freedom of speech and suggested it may even help reduce violence in future. "The fact is that bad things do go on in the world," she told AAP. Some of them are graphically violent - and that is a tragedy. But if places like Facebook ban the citizen reporting of these things, it doesn't make those tragedies go away. It just hides them from sight. That might in turn mean they continue to happen rather than being stopped. The best way to get social change is to reveal the truth, even if it's ugly. That's exactly why freedom of speech is so important. Dr Dreyfus said the boundaries of freedom of speech are increasingly being tested at "new coalfaces of digitally-based citizen journalism," like Facebook and Twitter. "Many corporations basically wimp it when they are asked to stand up on the hard issues like freedom of speech," she added. It's a good thing Facebook has opted for freedom of speech on this issue. News of Facebook's change emerged after complaints about a video purportedly showing a masked man killing a woman, which is believed to have been filmed in Mexico. Other social networking sites do allow graphic material to be viewed and shared - though most, including Facebook, operate complaint mechanisms whereby potentially offensive material can be reviewed and removed. The relaxation of Facebook's rules may be a move to bring it into line with the more liberal approach of its rivals.