In a recent case, we recovered a WiFi password for a client.
Why didn't she just reset the router?
The password was to a 3G WiFi router, which was hidden on the underside of a shelf the back of a cupboard and had been installed there by a 3rd party. It allowed this unknown 3rd party to connect remotely to a wireless surveillance camera we found, which was secretly installed nearby.
Once we had access to the router we identified the camera data traffic which alerted us to its presence. With access to the router, we were then also able to identify the IP address of the 3rd party who was remotely connecting to it.
A short time parked outside the home of a suspect, 'sniffing' wireless traffic. confirmed that he was the person accessing our client's home remotely.
A number of offences have been committed by this 3rd party, but our client preferred not to pursue legal action at this time.