It was set to be an illuminating online conversation with one of the world's most controversial figures.

But Al Jazeera's livestreamed talk with WikiLeaks founder Julian Assange was cut short on YouTube Thursday, inexplicably the victim of a copyright claim by NBC Universal.

Visitors who tried to watch the talk, hosted by Al Jazeera's The Stream, were greeted with the message "This video contains content from NBC Universal, who has blocked it on copyright grounds."

It's unclear what, exactly, that's supposed to mean, as NBC Universal and Al Jazeera are separate companies. The Stream tweeted to the Daily Dot that it "was an automatic block by YouTube which we're disputing." NBC Universal didn't respond to multiple requests for comment.

It's not uncommon for copyright holders to, following the Digital Millenium Copyright Act (DMCA), issue mass copyright claims on content they don't actually own. YouTube is a prime breeding ground for such takedowns, to many users’ frustration.

But though they have bred claims of censorship, DMCA takedowns, usually performed by third-party software, usually at least have a keyword that could trigger the system. Fox took down references to Cory Doctorow's novel Homeland, as the network owns a TV show of that same name. More embarrassingly, HBO's software once signed off on requests to censor search results for HBO.com, as it contained content copyrighted by HBO.

Viewers are, however, able to see Assange talk on Al Jazeera's site. DMCA takedowns can't reach that far.

Screengrab via CineFix/YouTube