The NSA gives an old spy trick a modern spin. And it involves radio waves

You might be starting to think there'd be little left in the National Security Agency bag of tricks that could surprise us.

And you'd be wrong.

The latest revelations about NSA spying involve secretly planting spyware inside some 100,000 computers around the world and using radio waves to access those computers, even if they're not connected to the Internet.

David Sanger co-authored a New York Times story about the program that was published Wednesday.

He says the basic concept is actually not new.

"All electronic devices emit some kind of radio wave," Sanger says. "And if you go back and you read about the early days of spycraft during the Cold War, you'll find that when people were typing on electric typewriters, the NSA and other agencies would frequently aim a radio wave at the windows of their offices because every key let out a slightly different radio emission and they could pick that up and figure out what was being typed. So you have to think of this as the next progression in that technology, or the one that can move more data far more quickly."

The new implementation allows American spies to access computers even if they aren't connected to the Internet — a security feature often used for sensitve machines. In fact, a receiver can be set up a great distance away that allows a spy remote access over long distances. But the system only works if special monitoring spyware is installed on the target machine — either by a spy, an unwitting user, or by the manufacturer.

And Sanger says American-made manufacturers, as well as cloud service operators, have taken a hit from these spying revelations. 

"I think that's one of Silicon Valley's biggest worries about the NSA program — that the Snowden scandal may be one of the first spy scandals that has a bigger economic and business impact than it does a diplomatic impact,"  he says.  "The US industry and the government are going to have to come to some kind of agreement about the degree to which the government is going to ask industry to engage in practices on their behalf, and the degree to which industry is going to try to frustrate government efforts by building better encryption that they believe the NSA couldn't crack." 

That, Sanger says, "is going to be a long struggle."