This would require me to figure out in advance what public data links me to what private-but-anonymized data. We know about the IMDB-Netflix connection because it was pointed out after the fact. What other links are there that I can't predict? What if I can be identified by which nights I stay home to watch a movie? Generalizing, the problem with anonymized data sets is that it is very, VERY hard to say with confidence that the data cannot be connected to a client.

That kind of data should not be released without consent.