Bluetooth Sharing section in Privacy.
http://cl.ly/image/1Q1r3b0j180S
http://cl.ly/image/2z033k1D0D1z
"Apps that have requested the ability to share data via Bluetooth will appear here. These apps can share data even when you're not using them."
Woah.
WOAH indeed!! Jobs was not kidding about being fanactical about privacy (See All Things Digital, last appearance interview)! Bravo.
Coming from the days of feature phone bluejacking, I was just like the rest of immature lads having wild fun. Sending an invite from my Ericsson T-39m to a MacBook on the GO Transit ... "BONUS: Get a free months pass to ride the GO Transit if you show this message to the operator within the next 30mins". (The drive from Toronto to Hamilton was roughly 65mins, the time sent left about 35mins left before arrival). Dude jumped up like a jack-rabbit to show the bus driver. I then realized how dangerous having this guy disrupt the drivers attention could've put all 40 passengers lives at risk. This was 7yrs ago.
I'm guessing by this setting Apple may have noticed a few applications continuously accessing/sharing data without users knowledge. This will ALSO further reduce battery life.