A US court has ruled that Google must hand over the information of any and all users who has ever viewed a video on YouTube, as part of the legal battle between Viacom and Google over copyright infringement.
The information to be handed over will contain the log-in IDs of users, their IP addresses, and details of the video clips they've viewed.
Although the ruling has been made in the US, it is probable that the viewing log will include all users of YouTube globally, totalling more than 12 terabytes of data to be handed over to Viacom.
The court also ruled that Google disclose the details of all videos that have been removed from the site for any reason.
Viacom, owner of MTV and Paramount pictures, launched a lawsuit against Google in March of last year, accusing YouTube of copyright infringement because it has been showing clips of the company's shows and movies.
In February of last year, Google was ordered by Viacom to pull about 100,000 alleged infringing clips from YouTube, and just weeks later in March, Viacom launched a massive lawsuit against the company.
Viacom is suing Google for $1 billion (500 million) plus legal fees, as it asserts that it has found at least 150,000 video clips from its company's productions on YouTube, constituting at least 1.5 billion views on the site.
US-based digital rights group the Electronic Frontier Foundation (EFF) called the ruling a "set-back to privacy rights," and urged Viacom to limit its requests in order to protect users.
"The Court's erroneous ruling is a set-back to privacy rights, and will allow Viacom to see what you are watching on YouTube. We urge Viacom to back off this overbroad request and Google to take all steps necessary to challenge this order and protect the rights of its users," the group told the BBC.
They also said the ruling was potentially unlawful because the log data contains personally identifiable data, but the court said privacy concerns about handing over the log were "speculative."
