• by Wendy Davis , Staff Writer @wendyndavis, September 4, 2012

For years, digital rights advocates have warned that automatic filtering systems could shut down completely legitimate videos, blog posts or other material online.

That's because copyright issues aren't always clear-cut. Content creators can incorporate copyrighted material in a way that makes fair use of it. And owners can authorize clips to be shown in some contexts, but not others. But technological filters can't always account for those nuances.

Now advocates can point to a high-profile example of filtering gone awry: Sunday night, Ustream shut off a Webcast of the Hugo awards -- given for science fiction and fantasy writing -- due to a filter snafu. The stream cut out just as Neil Gaiman was accepting an award for writing an episode of "Doctor Who." In place of the Webcast was the notice, "Worldcon banned due to copyright infringement."

How did this happen? io9 reports that the awards ceremony included clips of the episode Gaiman wrote. That material -- which, not surprisingly, is copyrighted -- was flagged as infringing by Vobile, an enforcement company used by Ustream.  As a result, the Webcast was stopped.

Ustream CEO and founder Brad Hunstable says that the company learned of the glitch right away, but wasn't able to resume the Webcast before the ceremony ended.

Hunstable adds that the company "suspended use of this third-party system until we are able to recalibrate the settings so that we can better balance the needs of broadcasters, viewers, and copyright holders."

Of course, Web sites shouldn't stream content that they know infringes copyright. But if sites expect to be considered reliable, they also need to make sure they aren't censoring material that's legitimate. In some cases, as Ustream found out, that might mean ensuring that staff has the ability to immediately override automated copyright tools.