Respectfully, there's geek-thinking again. Wifi password changing is a straw-man argument - most households use the default SSID and password that came with the router (if you don't believe me go to a residential area outside of SF and see how many 2WireXXX or ATTXXXX SSID's there are). Those that do set their own password never change it again.

Apps enabling multiple scanners - again assumes multiple smartphone ownership in the house in order for everyone to use it vs just having a single dedicated scanner that (as Amazon suggests in their site) hangs on your refrigerator.

I'm not even sure the average consumer is sufficiently trained yet about opening apps. I heard a segment on NPR recently where multiple callers (and the host) referred to a company's mobile-optimized website as an "app", many normal people don't really know what an app really is. I'll dig out the Pew Research study on mobile phones that said something like 20% of smartphone owners don't install any apps on their phones beyond those that came with the device (perhaps because they're fuzzy on the concept).

UPDATE: http://usatoday30.usatoday.com/tech/news/story/2012-01-30/sm... - 17% of smartphone owners don't use any apps at all according to Pew.