Industrial strength wireless solutions use a cryptograpic hash in the beacon frames called a Management Integrity Check (MIC) and if the client and AP don't pass the MIC, you can't get in even if you have the same SSID. Just wasn't sure if home wireless systems use the same type of features.
I image for people who live in a large high rise apartment buildings, you've got beaconing SSIDs all over the place and in many cases, your neighbors signal will appear stronger than your own. Probably safe for folks living in single family homes but if I lived in some Manhattan high rise, I wouldn't even beacon my SSID just to be safe.