Computer scientists in the US have discovered ways to "re-identify" the names
of people included in supposedly anonymous datasets.
In one example, a movie rental company released an anonymous list of
film-ratings taken from its 500,000 subscribers. Using a statistical "de-anonymisation"
technique, the academics were able to identify individuals and their film
The discovery raises concerns about how safe it is to release personal
information – such as medical records or mobile phone data – even if details
such as names or national insurance numbers have been removed. There are fears
the information could be accessed by criminals.