The US National Security Agency (NSA) has acquired the power to tap 3G and 4G smartphones - not only Apple iPhones and Android devices, but also supposedly secure BlackBerrys.
The revelation is the latest in a series of leaks orchestrated by whistleblower Edward Snowden and journalist Glenn Greenwald.
The news that even BlackBerry devices are vulnerable to security service tapping will be particularly damaging to the company as security is one of BlackBerry's key selling points.
The latest NSA leaks were published in German newspaper Der Spiegel as The Guardian newspaper in the UK is rumoured to have been gagged by "D-Notices" issued by the government.
"The documents state that it is possible for the NSA to tap most sensitive data held on these smartphones, including contact lists, SMS traffic, notes and location information about where a user has been," claims Der Spiegel.
It continues: "The documents also indicate that the NSA has set up specific working groups to deal with each operating system, with the goal of gaining secret access to the data held on the phones."
According to Der Spiegel, the documents indicate that, unlike the NSA's web spying apparatus, smartphone tapping has been targeted "in an individually tailored manner and without the knowledge of the smartphone companies".
However, in the past the NSA has been limited in its ability to spy on BlackBerry users, with documents from 2009 suggesting that the NSA was unable to access BlackBerry devices.
But a 2010 document shows that the company's security was cracked just a year later by technologists working at UK spy agency GCHQ, after BlackBerry changed the way that it compresses data.
"The documents also state that the NSA has succeeded in accessing the BlackBerry mail system, which is known to be very secure," claims Der Spiegel.
It is not clear, though, whether the company's latest BlackBerry 10 operating system and BlackBerry Enterprise Server 10 mobile management software have also been compromised.