When will people learn that you can't remove obvious identifiers and then expect that the result is anonymized data that won't breach anyone's privacy? Google (YouTube) will release "anonymized" data to Viacom as part of a court order regarding copyright infringements; see here.

If you have a short memory, here are two recent examples of what can be done to anonymized data. First, AOL released a huge amount of search keywords (in anonymized form), but it was quickly shown that the result was very far from anonymous. Second, Netflix released anonymized data for the Netflix prize, which too was completely deanonymized.

In short, data is not easily anonymized, and don't trust anyone who says that it is. In this specific case, the claim is that the data is not being released to the public, just to Viacom. So, what's the problem (I won't dignify this claim to even bother answering).