Intelligence agencies across Europe have been developing their own mass internet and phone surveillance capabilities in partnership with the UK's GCHQ electronic intelligence agency.
That is the latest claim to arise from the cache of US National Security Agency (NSA) documents released by whistleblower Edward Snowden.
Further reading GCHQ and NSA spying on Google and Yahoo users after cracking the companies' security NSA monitored 60 million Spanish calls, but denies claims President Obama knew about Merkel phone-tapping NSA accused of tapping French phones. And the Mexican president's emails NSA harvests millions of personal email and IM contact lists
The documents, reported in The Guardian newspaper, indicate that it isn't just GCHQ and the British government that has been directly tapping backbone internet communications links: German, French, Spanish, the Netherlands and Swedish intelligence services have also been engaging in clandestine mass surveillance activities.
"A loose but growing eavesdropping alliance has allowed intelligence agencies from one country to cultivate ties with corporations from another to facilitate the trawling of the web," claims The Guardian.
It continues: "The files also make clear that GCHQ played a leading role in advising its European counterparts how to work around national laws intended to restrict the surveillance power of intelligence agencies."
The latest revelation accounts for the muted protests when it was revealed that the NSA and GCHQ were tapping internet traffic wholesale, and even cracking the network security of internet companies such as Google and Yahoo in order to access more information.
It also follows hints from NSA director, General Keith Alexander, in testimony to the US Congress this week that European governments were being somewhat hypocritical in terms of the protests they had made so far. "Some of this reminds me of the classic movie Casablanca - 'My God, there's gambling going on here'," said Alexander.
In Sweden, laws passed in 2008 enables its intelligence agencies to monitor cross-border email and phone communications without a court order. The German government, meanwhile, has channeled most of its outrage into protesting over the tapping of Chancellor Angela Merkel's mobile phone calls.
The latest Snowden documents come from GCHQ via the NSA and assess the mass electronic surveillance of each country in Europe. Germany's Federal Intelligence Service (BND) was particularly advanced, according to the documents.
GCHQ has also been aiding Germany's intelligence services in changing laws to make it easier to bypass legal restrictions on their activities. "We have been assisting the BND (along with SIS [Secret Intelligence Service] and Security Service) in making the case for reform or reinterpretation of the very restrictive interception legislation in Germany," claim the documents.
The French secret services, meanwhile, had the advantage of a close relationship with an unnamed telecoms company. "'DGSE [the French equivalent of GCHQ] are a highly motivated, technically competent partner, who have shown great willingness to engage on IP [internet protocol] issues, and to work with GCHQ on a 'cooperate and share' basis'," The Guardian quotes the documents.
Indeed, GCHQ has even trained DGSE technicians on "multi-disciplinary internet operations".
The Spanish and Italian intelligence agencies had made least headway, according to the report published in The Guardian, with the Italians hamstrung partly by the legal environment, and partly by inter-agency rivalry.
The documents indicate that GCHQ has been encouraging intelligence agencies across Europe to engage in the same mass internet and phone surveillance that it has been practising since the mid-2000s, partly on behalf of the NSA.
