“When a computer running an older version of XP can’t find any of its ‘favorite’ wireless networks, it will automatically create an ad hoc network with the same name as the last one it connected to—in this case, ‘Free Public WiFi.’ Other computers within range of that new ad hoc network can see it, luring other users to connect. And who can resist the word ‘free?’”

Prevent security risks from stuff like Firesheep. “When you connect to the Internet through an unprotected wireless network, such as at a coffeeshop or an airport, where you don’t have to enter a security key, you’re putting yourself at risk. Attackers connected to the same network can easily intercept your unencrypted traffic and log in as you to services such as Facebook, Amazon, and LinkedIn.”