If people think that any of your data is anonymised or pseudo-anonymised, you really need to watch the HOC Health Committee of many examples that they can identify individuals.
See:
http://www.parliamentlive.tv/Main/Pl...eetingId=15289
Yes its a long vid, but interesting and an eye opener.
This is why release of data, be it health or HMRC. The more data out their the easier it is for you to be identified.
