The ongoing court case in the US between Google and Viacom over the use of copyright video content on YouTube has taken a notable turn this week as the judge has ruled that Google must reveal the viewing habits of every user on YouTube who has ever viewed a video. As reported by the BBC, the ruling means that Google must hand over the viewing log to Viacom, which contains the log-in ID of users, the computer IP address (online identifier) and video clip details.

This development clearly has major implications for online privacy and Google are now arguing about the format of the data and the need to conceal individual user's details. This depth of information shouldn't be necessary for Viacom, who want to assess the total viewing patterns of their content through YouTube (which includes clips from MTV and Paramount Pictures). They have previously claimed that about 160,000 unauthorised clips of Viacom's programmes were available on YouTube prior to 2007 and that these had been viewed more than 1.5 billion times.

Viacom had also requested access to Google's source code for YouTube, but the court turned down this, since it recognised that it was effectively a "trade secret" and therefore shouldn't be disclosed. However, Google hope that the court will allow them to anonymise the data on individual user habits - nevertheless, this ruling means that Viacom will have access to a huge amount of activity logs in what is becoming an increasingly bitter legal case between these 2 giant US companies.

The eventual ruling in the case is likely to become a landmark case in Internet history and potentially affect the way that online video sites can operate in the future.