The U.S. National Security Agency has been spying on Italian communications from installations on the roof of the U.S. Embassy in Rome and the country’s consulate in Milan and even mounted an operation to capture information from inside the Italian embassy in Washington, D.C., the Italian weekly magazine L’Espresso claimed Friday.

In a cover story titled “The Americans Spy on Us From Here,” the left-leaning magazine published photographs ostensibly showing a “concealed collection system” on the roof of the Rome embassy and top secret documents, apparently provided by the fugitive former NSA contractor Edward Snowden, that give details of the activities of the NSA’s Special Collection Service.

The allegations are likely to prove embarrassing for the government of Prime Minister Enrico Letta, who last month assured parliament there was no evidence that the security of Italian communications had been compromised, “neither those of government leaders, nor of our embassies, nor is there any evidence that the privacy of our citizens has been violated.”

A 2002 document cites in the article describes the function of the Special Collection Service as: “Covert SIGINT [Signals intelligence] collection abroad from official U.S. Government establishments, typically US embassies and consulates.” It says the NSA partners with the CIA for the program, with NSA employees operating under diplomatic cover. “Special Collection Sites provide considerable perishable intelligence on leadership communications largely facilitated by site presence within a national capital.”

The document says there were approximately 65 sites in existence, down from a peak of 88 in 1988. A later document, dating from 2004, mentions the existence of an SCS site in Rome and the intention to open another in Milan.

Written by Glenn Greenwald and Stefania Maurizi, the article quotes British espionage expert Duncan Campbell, who identifies a tent-like structure on the embassy roof as a SIGINT concealment. It likely contained “multiple antennae listening to mobile phones on GSM, GPRS, 3G, and CDMA; and to government and police channels; and supporting special activities by the CIA, such as targeted bugging,” Campbell said.

Another Snowden document, classified Top Secret/Noforn [not for release to foreign nationals], allegedly describes espionage operations directed against the Italian embassy in Washington. An operation code-named Lifesaver apparently involved “Imaging of the hard drive,” while another, Highlands, used “Collection from implants.” L’Espresso suggested the operation against the embassy may have run from 2004 to 2010.

”Ever since the NSA scandal broke, the United States has argued that the NSA mass surveillance program aims to protect the country and its allies from terrorism. But what does espionage against a friendly country have to do with the fight against al-Qaeda fundamentalism?” the magazine asked. “Italian governments have always been considered reliable on this front.”

L’Espresso published a slide allegedly showing the collection of communications metadata in Italy in December 2012. The document shows a peak of collection, of around 4 million telephone metadata per day, coinciding with the political crisis that brought down the government of Mario Monti and a very low level of collection over the Christmas holidays.

Claudio Fava, a leftwing member of the lower house of parliament, Friday expressed skepticism about the usefulness of the NSA’s electronic eavesdropping in the fight against terrorism. “There’s a spike in collection that coincides with the Monti government crisis and almost zero collection on December 24,” Fava told participants at a conference on “Datagate and Privacy” in Rome. “That’s not because terrorists respect Christmas, but because government offices are closed.”

Antonello Soro, the president of Italy’s Privacy Authority, was also critical of U.S. behavior, which had produced the paradox of a massive violation of individual liberties by a democratic government seeking to fight terrorism and defend those same liberties. The result was to set a bad example to countries where democracy was not firmly rooted, Soro told the same Rome conference.

Stefano Rodota, Soro’s predecessor at the Privacy Authority, agreed. “It seems to me that the ability to handle this issue at a general level is debatable, but in Italy it’s close to zero,” Rodota told the conference.

Fava said Italy had once again shown a supine attitude in its dealings with its most powerful ally. “The government should have summoned the ambassador to demand an explanation,” he said, during a pause in the conference. “The Italian government never opposes the wishes of its American ally, and that doesn’t gain it more respect. The Americans treat Italy as their own back garden.”

L’Espresso said it had contacted the NSA for comment but the agency had declined to address specific alleged intelligence activities. “The U.S. government has made clear that the United States gathers foreign intelligence of the type gathered by all nations,” NSA spokeswoman Vanee Vines told the magazine by email.