There is still some questions out there about Bluetooth and security. Bluetooth 4.0 and now 4.2 is whole different animal than classic Bluetooth. In fact since being adopted by IOS and Android and the plethora of smart connected devices..things have taken off in high gear to say the least. Any connected device from a wireless perspective just needs to make this part of their strategy.
While this white paper is coming from an manufacture, it does provide a good technical guide surrounding security and privacy. It is not coming from "marketing" but from "field engineering".