If you have a Facebook account, you MUST read this.
Facebook hit with porn and violent images 'virus'
Facebook has said that it is investigating reports that pornographic and violent images have been posted on the social network in members' news feeds.
Technology website ZDNet reports that the material is being spread via a "linkspam virus", which encourages users to click on seemingly innocent story links.
The virus could possibly have expanded so quickly via "clickjacking", a process involving a user clicking on an image and inadvertently sharing it on their own news feed.
Facebook said that it is "aware of these reports" and confirmed that it is "investigating the issue".
In an emailed statement, a Facebook spokesman added: "Protecting the people who use Facebook from spam and malicious content is a top priority for us and we are always working to improve our systems to isolate and remove material that violates our terms.
"We have recently experienced an increase in reports and we are investigating and addressing the issue."
Thousands of Facebook members have turned to microblogging website Twitter to post comments about the security breach.
"Discovered a new porn site, it's called Facebook," posted one user.
Graham Cluley, a consultant at internet security firm Sophos, said today that "explicit and violent" images had been flooding the news feeds of Facebook users over the past 24 hours.
Writing on the Sophos blog, Cluley said that images included hardcore porn and photoshopped images of celebrities, including 17-year-old singer Justin Bieber, in sexual positions.
He said that the violent images included a photo of an abused dog and other mutilated animals.
"It isn't presently clear precisely how the offending content has been spread - whether users are falling for a clickjacking scheme, are being tagged in content without their knowledge, have poorly chosen privacy settings, have been tricked into installing malicious code, or have fallen victim to another vulnerability inside Facebook itself," wrote Clueley
"What's clear, however, is that mischief-makers are upsetting many Facebook users and making the social networking site far from a family-friendly place."
Several people are linking the attack to the Anonymous hackers after a video appeared on YouTube supposedly from the group threatening to "kill" the social network. But experts have since doubted the authenticity of the video.
Cluley called on Facebook to urgently tackle the spread of offending content, or potentially face long-term consequences, as some users have already indicated that they will cancel their accounts.
"It's precisely this kind of problem which is likely to drive people away from the site," he wrote.
"Facebook needs to get a handle on this problem quickly, and prevent it from happening on such a scale again."