A video of unknown origin appearing to show a grown man sexually abusing an infant girl went viral overnight on Facebook, garnering as many as 32,000 shares and over 5,000 likes before finally being removed by the website.

According to users who came into contact with the video — whether through their newsfeed or on various Facebook forums — it took over eight hours for Facebook's clean-up crew to eliminate the disturbing footage from its servers.

For its part, Facebook claims it worked "swiftly" to delete the video, saying in a statement, "we have zero tolerance for child pornography being uploaded onto Facebook and are extremely aggressive in preventing and removing child exploitive content."

Testimonials on Twitter from users subjected to the criminal content would suggest a failure of Facebook's supposed "state-of-the-art" firewall, which received much attention when it was first implemented two years ago.

Facebook later upgraded its early-warning system with Microsoft's PhotoDNA, following reports that many pornographic images involving children were being regularly shared around the social network.

It's interesting to note that many of those sharing the abuse video appear to have been doing it out of disgust rather than appreciation.

One person who shared an alleged screenshot from the video captioned their post with "MUFUCKAS SICK shyt just ruined my day."

It's unclear why they wouldn't just report the video to Facebook rather than seek to ruin other people's day as well.

[tweet via @SimplyHarmonyxo]