Late last night, a live broadcast by Sky News was taken offline by a copyright claim made by Fox News. It isn't clear if Fox News manually made a copyright claim against Sky, or whether this was just a particularly hilarious case of YouTube's automated Content ID system gone awry. If you weren't aware, Sky News and Fox News both share the same parent: 21st Century Fox, the spiritual and legal successor of Rupert Murdoch's News Corporation.

Last night, Sky News was broadcasting a debate between the US Republican presidential candidates, including Donald Trump, Jeb Bush, and Rand Paul. Sky News uses YouTube for its live Internet feed, rather than its own platform. At some point, the YouTube feed was replaced by black static and an error message: "This video is no longer available due to a copyright claim by Fox News Networks, LLC."

Sky News has since switched over to a new YouTube URL and is broadcasting normally. The old URL is still online, however, showing the copyright claim by Fox News.

As to why Fox filed a copyright claim against Sky, we can only guess. Neither company has yet issued a statement.

YouTube's Content ID system, which lets rightsholders algorithmically assert copyright claims against potentially infringing videos, has been known to make mistakes in the past. Back in 2012, it famously blocked a video of the Curiosity rover uploaded by NASA. After a number of similar gaffes, YouTube said that it had updated the Content ID system to require manual human intervention in some cases.

Another possibility is that Fox News (or someone at Fox News) really did file a copyright claim against Sky News. Last night's Republican debate, which was hosted by Fox News in partnership with Facebook, was meant to only be available to those with a cable TV subscription. It wouldn't be all that surprising if someone at Fox News took umbrage with Sky News offering a free live feed of the debate on YouTube.

We'll update this story with more information as we get it. Sky News hasn't yet responded to our request for comment.