'Free Public WiFi' Isn't a Normal Wireless Network. It's a Zombie.
Free Public WiFi, you see, isn't your average wireless network. It's an "ad hoc" network, meaning that, when you connect to it, you aren't connecting to a wireless router, but to someone else's computer within your immediate vicinity. As NPR explains, Free Public WiFi appears to have arisen from a bug in an older version of Windows XP. When a computer running this version of XP can't find one of its preferred networks, it creates a new ad hoc network, which it automatically names after the last network it joined. Because this new network is visible to others within range of the XP-equipped computer, others can "join," thereby allowing the name to spread in much the same way that a zombie spreads living death by biting people. At one point, then, someone must have created the 'Free Public WiFi' ad hoc name, which clearly succeeded in luring other users to join.
Unlike zombies, however, Free Public WiFi won't eat your computer's brains. In fact, there's nothing inherently malicious about joining the network, or other common ad hoc creations like 'linksys,' 'hpsetup,' 'tmobile' or 'default.' Wireless security expert Joshua Wright speculates that it was probably created by someone looking to pull off an innocent joke, in an attempt to lure a friend into joining "so he would get a Web page with some kind of a gross image or childish prank."
Still, Free Public WiFi and its zombie brethren could provide an easy way for hackers to infiltrate and corrupt our hard drives. The vulnerability is so obvious, in fact, that it's a veritable red flag for security experts looking to tighten up a company's wireless network. As Wright explains, whenever he and his team of experts see the name Free Public WiFi pop up on a company's list of available networks, "we break out the champagne."