The spokesperson for Russian President Vladimir Putin today denied a foreign media report that Russian intelligence tried to use booby-trapped complimentary USB sticks and phone chargers to spy on the communications of G20 members during last month's summit in St. Petersburg - a sly cyber tactic familiar to Western security officials.

"We don't know the sources of the information," Russian presidential spokesperson Dmitry Peskov told Russia's state-owned RIA Novosti. "However, this is undoubtedly nothing but an attempt to shift the focus from issues that truly exist in relations between European capitals and Washington to unsubstantiated, non-existent issues."

The allegation against Russia, printed in a major Italian newspaper, comes on the heels of other international reports that the U.S. National Security Agency collected information on tens of millions of communications by European citizens. NSA chief Gen. Keith Alexander called those reports "completely false" at a Congressional hearing today. Alexander said the data was actually collected by foreign partners and was information "that we and our NATO allies have collected in defense of our countries and in support of military operations." Alexander said the foreign media and their source, reportedly former NSA contractor Edward Snowden, "did not understand what they were looking at."

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A former U.S. government official told ABC News that American officials are "routinely advised" to discard any USB sticks given as gifts by foreign organizations or governments - especially fancy, gold-plated ones - because they can be loaded with secret Trojan viruses. A booby-trapped USB stick is one method in which cyber attackers can spy on, or even take over, targeted computer networks - even hyper secure networks that are not connected to the internet.

In 2011 Bloomberg reported about an experiment in which the Department of Homeland Security dropped computer disks and USB thumb drives in parking lots of U.S. government buildings just to see how many government employees would pick them up and plug them in to their office computers, potentially compromising the network. Sixty percent did, according to Bloomberg, and the number jumped to 90 percent if the CD or thumb drive had an official logo on it.

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