Oh, and as a side note - you can see in this image that is a simple report from my WLC, not only do I see their SSID, I also see their MAC. So, if I was a criminal (and I am not) it would not be hard to spoof their mac, take over their internet and do as I wished.
Securing an SSID is step one. Step two is not broadcasting the SSID, then MAC level IP's on devices. NOT using 192.168.1.x and so many others...
(Note: this report is a simple tool included with all WatchGuard, Cisco, and may other higher end firewalls and Wireless LAN controllers).