Anonymisation

Truly anonymous data is much harder to produce than people assume, and the word gets used for things that are not.

Removing names and email addresses is not enough. Unique combinations of perfectly ordinary details, a postcode, a date of birth and a sex, identify a startling proportion of a population on their own. Add location traces or browsing history and re-identification becomes routine. If the data can be traced back to an individual by anybody, with reasonable effort, then it is still personal data and the law still applies to it.