Reply #4: From what I picked up from the book, Chatter, yes.

[politicat]

Basically, the process is that it pulls a copy of the signal sent via microwave - and since 99.99999% of the signal goes where it's supposed to go, there's no effective degradation of the signal. It's like the fact that your neighbor one house closer to the radio station having his radio tuned to the same as yours doesn't mean that your radio signal is degraded. They're not actually listening to specific calls, but monitoring all of the network traffic carried on a certain frequency. (The difference between following a car with a specific license plate because you think it might be involved in a hit and run, and writing down all of the license plates you see in a day because any of them could be involved in a hit and run. The first would probably be called stalking. The last is just crazy because the signal to noise ratio is so extreme.)

The book I read about SIGINT (okay, listened to, while driving to Indiana and back) was called Chatter, by Patrick Radden Keefe, and is here: http://search.barnesandnoble.com/booksearch/isbnInquiry.asp?userid=dK8oCX8B72&isbn=1400060346&itm=1

I am not a signals intelligence expert. Hell, I'm barely even moderately knowledgeable. I'm just quoting the book and drawing analogies.

The thing is, once something is broadcast, according to these spy types, the user loses the assurance that it's private because it has been broadcast (even though detecting the broadcast is incredibly difficult.) It's one of the reasons I'm becoming a fan of VoIP phones and have gone back to writing letters -- why should I make it easy?