Viacom vs YouTube exposes Google's data retention policy

In the ongoing litigation between Viacom and YouTube (Google) over alleged copyright infringement, a US court has ruled that "Google must divulge the viewing habits of every user who has ever watched any video on YouTube", reports the BBC.

The one thing that bothers me more than the court ruling itself, however, is the fact that Google retains this amount of user data in the first place. Because Google insists on keeping wide-reaching records of the surfing habits of its millions of users - presumably for ad-targeting purposes - in cases like this it's left open to Google, and Google alone, to defend our privacy. If Google didn't keep such logs, then Viacom or anybody else, couldn't access our viewing habits.

Specifically, the Logging database that Viacom will have access to contains:

... for each instance a video is watched, the unique “login ID” of the user who watched it, the time when the user started to watch the video, the internet protocol address other devices connected to the internet use to identify the user’s computer (“IP address”), and the identifier for the video.

Naturally, Google argued in court such data "should not be disclosed because of the users’ privacy concerns", but this proved to be futile. Again, wouldn't it be better not to keep such records in the first place? Instead, privacy isn't an issue if the data is in Google's hands - the company can do no evil - it's just if any of its competitors get their grubby hands on it.