Changing their router or even turning it off won't necessary help. Here is a way to reproduce this issue and explain my point: if you are a thief, you could se

Changing their router or even turning it off won't necessary help. Here is a way to reproduce this issue and explain my point: if you are a thief, you could setup a GPS spoofer pointing to that house or have had your router in that house in the past so that some phones registered/verified it's MAC address to be at the house location. Now assume the thieves live in a location where they took this router with them and where there is no GPS signal or other router or cell signal, but only the thieves' router turned on. Now as soon as the thieves connect the stolen phones to their router, they will report being at the house. My bet is that this is likely an intentional attack by the thieves and that they are aware of what they are doing. There is a small chance they could have been people living in the house before or drove by to setup their spoof as it would have been much easier than getting their hands on a GPS spoofer.