Blah blah ECHELON blah
Didn't help toward the tail end of 2001, did it?
How does ECHELON track the source of a message sent via onion to a directional radio, disguised as 35mhz model aircraft servo noise, to onion again, through the compromised computer of someone who thought they were getting free porno, bounced around inside the data centre of an admin who thought that USB mouse in the post really was a free manufacturer sample, out to an embedded system stuck in a tree with a solar panel, through someone's compromised wifi router and galivanting merrily on its way to a botnet stolen through the use of clever Google searches, embedded into a jpeg as slightly shifted luminance values and then recieved by some guy in a 3rd world country with a satellite downlink accessing the web server on one of the botnet nodes?
It might not exactly be Skype, but you don't really need much bandwidth to say "the plan is go, Ahmed."
Question is whether you need to trace the message at all.