Documents leaked by former NSA contactor Edward Snowden suggest that spy agencies have a powerful ally in Angry Birds and a host of other smartphone apps.
The documents, published by The New York Times, The Guardian, and ProPublica, suggest that the mapping, gaming, and social-networking apps common on the world's estimated one billion smartphones can feed America's National Security Agency (NSA) and Britain's GCHQ with huge amounts of personal data, including location information and details such as political affiliation or sexual orientation.
The size and scope of the joint spying programme are not publicly known, but the reports suggest that US and British intelligence easily get routine access to data generated by apps such as the Angry Birds franchise or the Google Maps navigation service.
The programme "effectively means that anyone using Google Maps on a smartphone is working in support of a GCHQ system", one 2008 document from the British eavesdropping agency is quoted as saying. Another document - a hand-drawn picture of a smirking fairy conjuring up a pile of papers over a table marked "LEAVE TRAFFIC HERE" - suggests that gathering the data does not take much effort.
The NSA did not directly comment on the reports but said in a statement that the communications of those who were not "valid foreign intelligence targets" were not of interest to the spy agency. "Any implication that NSA's foreign intelligence collection is focused on the smartphone or social-media communications of everyday Americans is not true," the statement said. "We collect only those communications that we are authorised by law to collect for valid foreign intelligence and counterintelligence purposes - regardless of the technical means used by the targets."
GCHQ insisted that all of its activities were "authorised, necessary and proportionate".
Intelligence agencies' interest in mobile phones and the networks they run on has been documented in several of Snowden's previous disclosures, but the focus on apps shows how innocuous-looking software can be used for espionage.
Angry Birds is an addictive birds-versus-pigs game downloaded more than 1.7 billion times worldwide. But one NSA document listed other apps made by Facebook and Flickr.