The phone, internet and email records of UK citizens not suspected of any wrongdoing have been analysed and stored by America's National Security Agency under a secret deal that was approved by British intelligence officials, according to documents from the whistleblower Edward Snowden. In the first explicit confirmation that UK citizens have been caught up in US mass surveillance programs, an NSA memo describes how in 2007 an agreement was reached that allowed the agency to unmask" and hold on to personal data about Britons that had previously been off limits. The memo ... says the material is being put in databases where it can be made available to other members of the US intelligence and military community. Until now, it had been generally understood that the citizens of each country were protected from surveillance by any of the others. But the Snowden material reveals that: In 2007, the rules were changed to allow the NSA to analyse and retain any British citizens' mobile phone and fax numbers, emails and IP addresses swept up by its dragnet. These communications were "incidentally collected" by the NSA, meaning the individuals were not the initial targets of surveillance operations and therefore were not suspected of wrongdoing. The NSA has been using the UK data to conduct so-called "pattern of life" or "contact-chaining" analyses, under which the agency can look up to three "hops" away from a target of interest - examining the communications of a friend of a friend of a friend. Three hops for a typical Facebook user could pull the data of more than 5 million people into the dragnet.