2011 Apr 8, 2:07
"On average their method gets to within 690 metres of the target and can be as close as 100 metres – good enough to identify the target computer's location to within a few streets.", "When a landmark
machine and the target computer have shared a router, the researchers can compare how long a packet takes to reach each machine from the router; converted into an estimate of distance, this time
difference narrows the search down further."