My money is on a wifi SSID that matches the one used by thieves or a heavily-trafficked location the victims all pass through. My company moved ~5 blocks and it really screwed up the map on my phone (which I use to get around the city) for several months. My company had left the network SSID the same in the old location, so that no one had to re-configure their wifi. Even with GPS on, my phone was always convinced it…
It seems much more likely that there is some bogus location data set somewhere that improperly links SIDS and GPS coordinates or filters fail and result some index into a GPS table that happens to correspond to this couple's home. If I were these two people, I'd contact the local police department every single time anyone shows up at their house and require that the PD fill out a report of some kind and keep it in a…
It might make some people more suspicious ('maybe this is how they cover it up'), but should send most people on your way. Your idea of having a police report on file and contacting the local police department is even better.