I'm not fully up to speed with all the research here, but as far as I understand it's quite easy to de-anonymize many datasets of exactly the kind you describe.

I'm not fully up to speed with all the research here, but as far as I understand it's quite easy to de-anonymize many datasets of exactly the kind you describe. If you're not really, really careful there will be lots of information in simple demographic data that could easily be matched to other data sources.