Corporations, like Target, can't track users if they have bluetooth disabled. Keeping bluetooth "always on" will make it easier for them to passively track iOS11 shoppers as they travel through their stores (whether they use the app or not).
https://techcrunch.com/2017/09...

v54 was still slow for me and I've been using the Developer version that had it enabled. I finally identified that e10s easn't enabled due to Mozilla's "Mozilla Archive Format" addon.
http://maf.mozdev.org/

As far as I know, this is the only browser-based plugin that supports the MAFF archive format. It hasn't been updated whereas other developers were required to update their addons. I'm not sure if this means that MAFF is dead or if its just an oversight. (I've tried reaching out via email & Twitter over the past couple of months, but there's been no response.)

Out of frustration regarding browser performance & non-communication, I finally switched to Chrome.

This hasn't been covered yet and I doubt that this information is being logged directly on the device.

I noticed that after upgrading iPhone4 to iOS 4.3.1, that the iPod app would attempt to connect to multiple iTunes servers while I was listening to a MP3 that I purchased on Amazon.com. (This background connection didn't occur when was using iOS 4.1.) I'm not sure why a connection needs to be made to the iTunes server to play a song locally on the device that wasn't purchased from their proprietary store. I'm not sure what data is being sent as I've been too busy to research it. I searched Google and haven't found any information regarding this. I used "Firewall IP" (a jailbreak app) to block the unauthorized reporting of this playback information. (Apple may have authorized this connection, but I don't.)