It's possible that the Hacking group Lulz have struck again and hit the government right between the legs. On their Twitter page they have reported this
We have blissfully obtained records of every single citizen who gave their records to the security-illiterate UK government for the 2011 census We're keeping them under lock and key though... so don't worry about your privacy (...until we finish re-formatting them for release)"
Are you worried about all that personal information you gave, that the government promised would be safe?
Below is the link to the story: http://www.theregister.co.uk/2011/06/21/uk_census_lost/