Shortly after launching an attack on the website of the Serious Organised Crime Agency, a message purporting to come from the hacker group LulzSec says it has taken data given by UK citizens in this year's census.
The statement said LulzSec had "blissfully obtained records of every single citizen who gave their records to the security-illiterate UK government for the 2011 census", and would release it all online.
"We're keeping [the details] under lock and key though... so don't worry about your privacy (...until we finish re-formatting them for release)," the statement by 'Cap'n Pierre Dubois' read. "Myself and the rest of my Lulz shipmates will then embark upon a trip to ThePirateBay with our beautiful records for your viewing pleasure!"
[UPDATE: In multiple Twitter posts, LulzSec has denied that it was behind the census data hack claims. In one, the group said the style of its notices had been copied, while another stated: "Just saw the pastebin of the UK census hack. That wasn't us — don't believe fake LulzSec releases unless we put out a tweet first."
A third message read: "But hey, if someone out there hacked the UK government in the name of #AntiSec, well done sirs!"]
In a statement, the Census Office said it was "aware of the suggestion that census data has been accessed", and was "working with our security advisers and contractors to establish whether there is any substance to this".
"The 2011 Census places the highest priority on maintaining the security of personal data. At this stage we have no evidence to suggest that any such compromise has occurred," the office said.
Organisations involved in the collection and processing of the 2011 Census data include UK Data Capture, the Office for National Statistics, and weapons-maker Lockheed Martin.
LulzSec and rival group Anonymous have formed an alliance on an operation called AntiSec, or Anti-Security, the primary purpose of which is to "steal and leak any classified government information".
Anonymous has its own successful history of attacks, but LulzSec has within a couple of months chalked up hits on the CIA, the US Senate, the NHS and various entertainment and games companies.
A UK teenager was arrested on Monday night in connection with network intrusions and distributed denial-of-service attacks against international businesses and intelligence agencies, but the Metropolitan Police has made no link between that arrest and the work of LulzSec or Anonymous.