YouTube viewer details to be supplied to Viacom
A judge in New York has said that Google must pass on the details of more than 100 million people - many of them in the UK - to Viacom, the US TV company that Google is involved in with a billion-dollar court case.
The argument is that Viacom's "experts" need to data in order to conduct a detailed examination of the viewing habits of millions of people around the world.
As well as internet addresses and email accounts, the data will contain info on the history of every video watched on the website.
Civil liberties campaigners are up in arms over the decision that will see an unprecedented amount of personal info turned over to a private company.