Finally, Wi-Fi clients can be too friendly, connecting to any AP and using sensitive apps without requiring server authentication. Tools like Karma, AirPwn, and Wi-Fish Finder can find clients vulnerable to Wi-Fi based (Evil Twin) man-in-the-middle attacks and teach you about their consequences. Our favorite is Karmetasploit: Karma, running on the Metasploit Framework. If you're responsible for securing Wi-Fi clients and haven't seen this one in action, you really should check it out.