Story highlights Livestream of Hugo Awards was cut short by copyright-protection software

The webcast, on streaming-site Ustream, showed scenes from "Doctor Who"

Ceremony had permission to use clips, but Ustream didn't know

Writer Neil Gaiman was accepting an award when the stream blacked out

On Sunday, the live Web broadcast of perhaps the world's most prestigious science fiction awards ended up in the Twilight Zone. Blame it on an attack by 'bots.

The Hugo Awards were being streamed live on video site Ustream when, at 10:43 p.m. ET, the feed went dark during an acceptance speech by fantasy writer Neil Gaiman.

The reason? Ustream says automated software designed to detect the unauthorized posting of copyrighted material was triggered when, before Gaiman's speech, the ceremony showed clips of "The Doctor's Wife," an episode of the popular sci-fi series "Doctor Who," that Gaiman penned.

Instead of Gaiman, text reading "Worldcon banned due to copyright infringement" appeared. Worldcon is the conference at which the awards are held.

"Our editorial team and content monitors almost immediately noticed a flood of livid Twitter messages about the ban and attempted to restore the broadcast," Brad Hunstable, CEO and founder of Ustream, wrote on the site's blog. "Unfortunately, we were not able to lift the ban before the broadcast ended. We had many unhappy viewers as a result, and for that I am truly sorry."

The third-party system, Vobile, is used by video sites to detect unauthorized posts. The Hugo Awards had permission to air the clips but apparently had not notified Ustream.

Hunstable acknowledged that his site's system for doing so wasn't as clear as it should be. He said the automated system has been suspended until Ustream is able to "better balance the needs of broadcasters, viewers, and copyright holders."

"Ustream is committed to promoting Internet freedom, and we will strive to continually improve our service to provide the best, legal viewing experience possible," he wrote.

Perhaps as a boon to disappointed fans, Gaiman, a prolific Twitter user with more than 1.7 million followers, shared a link Monday to his video acceptance speech from when he won the SFX Award for screenwriting in February.

"Copyright bots switched off the Hugo Award stream last night," he wrote.

Named after Hugo Gernsback, the editor of groundbreaking sci-fi magazine Amazing Stories, the Hugos (originally the Science Fiction Achievement Awards) have been awarded annually for science fiction and fantasy writing since 1953.

Gaiman, whose "Doctor Who" episode explored the doctor's most longstanding relationship in an unprecedented way, is known for the groundbreaking "The Sandman" graphic novel series and books like "Neverwhere," "American Gods" and "Coraline," which was turned into an Academy Award-nominated animated film in 2009.