This is potentially huge. Viacom, which owns MTV and Paramount Pictures, has been involved in a legal battle with YouTube (and now Google) over what Viacom alleges is massive copyright infringement of their property. Viacom claims to have identified 160,000 unauthorised clips of its programmes.

Now, a US court has told Google that it must hand over the a detailed log – some 12 terabytes of data – which contains the log-in ID of all users, as well as their IP address and information on all the video clips they have ever watched. The Electronic Frontier Foundation (EFF), a digital rights group, has called the ruling “a set-back to privacy rights.”

And it is. I mean, there’s nothing really explicit or illegal on YouTube (I think), but the idea that a corporation has the right to snoop around the viewing habits of everybody, just because 160,000 clips, out of an estimated 1.5 billion YouTube video clips, may or may not contain copyright material, is pretty scandalous.

It’s not just Viacom, either; the UK’s Premier League is also filing a lawsuit against Google claiming that YouTube has been used to show football highlights. I mean, really – highlights? What’s the big deal?

YouTube has responded by initialising new filtering tools to prevent copyright materials being uploaded to their site. Last time I looked, they didn’t appear to be working too well.

A spokesman for the EFF said, “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.”

How long until YouTube ‘does a Napster’, and becomes a shallow, big business-friendly version of itself (i.e., with no users), or disappears altogether? All it’s going to take is a Viacom victory – or whoever else decides to go to bat against Google. Until then, be careful what you watch – do you really want Viacom to know that you’ve seen the laughing baby ten thousand times?