The new Control Center on iOS 11 doesn’t completely turn off your Bluetooth and WiFi, when you use the toggles on it. According to reports, in its newest operating system, Apple allows users to toggle the settings off, but doesn’t actually turn the radios off completely, so as to allow some functions, including Airdrop and more to keep on working. So, while turning Bluetooth and WiFi off will let you disconnect a Bluetooth speaker, the radios will remain turned on.
On the one hand, this means they will drain the phone’s battery more. But more importantly, it could lead to security and privacy issues. Apple apparently leaves the two functions running for features like AirDrop, Handoff, geolocation and even to stay connected to an Apple Watch. That though could be useful, since you’ll not be accidentally disconnecting an Apple Watch when you don’t want to.
The change was first noticed by Andrea Barisani, a security researcher, who pointed out that disconnecting Bluetooth and WiFi are good practices from a security point of view.
You can of course turn the settings off completely still. To do this, users will have to navigate to each of these options within Settings. Here, you can switch off the respective connections by using the switch provided by Apple.