The question is how anonymous is your data once stripped of ‘personal identifying information’ (PII) when used by data aggregation companies for analysis. PII can include name, postcode, etc. I made a couple of blog posts in 2008 concerning this. According to a study led by the Children’s Hospital of Eastern Ontario, previously anonymised data were able to be correlated again from patient prescription records rending the anonymising process ineffective and a threat to patient privacy.
One Reply to “How anonymous is your anonymised data?”
We currently have a problem in the UK with the Information Commissioner’s interpretation of ‘anonymised’ youth justice data. It’s complicated to explain briefly, but you might want to look at this: http://archrights.wordpress.com/2009/09/23/when-is-anonymous-not-anonymous/