lammert - 12:56 am on Apr 16, 2011 (gmt 0)
If it was the technique described in that linked thread, coopster's routers would be positioned in the new country. But instead Google still thinks that the routers are in the US, in their original location. That is an indication that something fixed to the router is causing the positioning, rather than network delay time calculation what that thread is talking about. MAC address seems the most logical choice.