Your Wi-Fi can tell people a lot about you
Simply booting up a Wi-Fi-enabled laptop can tell people sniffing wireless network traffic a lot about your computer--and about you.
Soon after a computer powers up, it starts looking for wireless networks and network services. Even if the wireless hardware is then shut-off, a snoop may already have caught interesting data. Much more information can be plucked out of the air if the computer is connected to an access point, in particular an access point without security.
"You're leaking all kinds of information that an attacker can use," David Maynor, chief technology officer at Errata Security, said Thursday in a presentation at the Black Hat DC event here. "If the government was taking this information from you, people would be up in arms. Yet you're leaking this voluntarily using your laptop at the airport."