That's one of the reasons I went with wifi switches, even though they only control my exterior lights, it's still nice to known it's WPA2.
I guess you could sit around my house for ages sniffing packets to try to get in, but between the amount of traffic on my network, where I live, my farmer neighbors and my dog, you're going to have a welcoming comity well before you get enough packets to get into my network, and any drop and retrieve packet sniffer is going to run out of batteries right quick between the cold and my lack of wifi traffic.
Seemed like the 900ish MHz stuff just transmits in the clear right? So anyone with a reciever could snag the commands for your garage or security or locks??
Not 100% sure? Is that the case??