In the latest cautionary tale involving the so-called Internet of things, white-hat hackers have devised an attack against network-connected lightbulbs that exposes Wi-Fi passwords to anyone in proximity to one of the LED devices.......http://www.technotification.com/2014/07/wi-fi-hacking-with-bulb.html
This was my biggest worry when I got some Philips Hue Bulbs. I know it would be more expensive but I wish these "smart devices" would use WiFi to communicate instead of Zigbee or what-ever-other-standard they want to use. These standards just haven't been reviewed as much as WiFi and, alot of them are flawed. At least with WiFi we know WPA2 is secure if configured right. Personally I just run my lights over a different Wireless AP that has no access to anything else (not even internet). This way I get to use cool tech, and not worry about a security breach as much.