The SETI@home project invites volunteers to install special software of their home computers. This software, called BOINC, runs computational jobs when the computer would otherwise be idle. And the software needs to contact the main server periodically to deliver results and obtain new problems. Someone stole a laptop with this software. When it "called home" the owner tracked it down. There is a link to the story on the SETI page, but that link seems to be dead. But this link seems to be working.