This is no ordinary pineapple. It can actually hijack people’s wireless connections and get them to use the pineapple to connect to the internet instead of the router they meant to connect to—and then monitor what they are doing.
Simply put, when your computer turns on the wireless radio send out out beacons. These beacons say “Is such-and-such wireless network around?” Jasager, German for “The Yes Man”, replies to these beacons and says “Sure, I’m such-and-such wireless access point — let’s get you online!”
Of course all of the Internet traffic flowing through the pineapple such as e-mail, instant messages and browser sessions are easily viewed or even modified by the pineapple holder. The WiFi Pineapple is a specially crafted, battery powered wireless hacking device based on the Fon 2100 access point and housed inside of a plastic pineapple.
These beacons happen when your PC is setup to use a hidden wireless SSID, which you really shouldn’t do.