Polo van der Putt wrote a blog on IT en Recht (the free Dutch internetforum for IT and Law) on the recent Smart TV ruling of the Dutch Data Protection Authority. Amongst others the definition of personal data was stretched, also including sets of data of potentially various persons, as long as they can also be related to a certain individual, irrespective of whether the name of this individual is known.
The (dutch language) blog can be found here.