The SETI@home project uses Internet-connected computers operating in a grid to analyze radio telescope data for signs of extra-terrestrial intelligence. But as Minnesotan developer James Melin discovered, it can also be used to find... a stolen laptop and a not-so-intelligent terrestrial thief.
After his wife's laptop (which was running the SETI@home software) was stolen from their home on January 1st, Melin noticed that the computer had checked in three times to the SETI database. So obviously, whoever stole it had simply logged onto the net and hadn't bothered to disable the service. Melin determined the IP address and sent it to police, who were able to determine the real-world address where the laptop was plugged in. Within days the laptop was recovered, with all data intact.
Many free and commercial geolocation services are available to turn IP addresses into earthly coordinates but they're not accurate enough to give you a house address. For that the police, armed with a subpoena, turned to the local Internet service provider.
Source: Associated Press