Data Gathered by	Phone Type	Defense	Cost/Effort/Tradeoff
Ultrasound	Modern smartphone	No microphone access	Hard to turn off app-by-app
Bluetooth		Turn off bluetooth	Toggles at OS level (note changes to iOS11)
Wifi		Turn off wifi	Toggles at OS level (note changes to iOS11)
Apps		Turn off per app	May differ by OS
Location	Android	Turn off location	Android users in TM session reported this is tough to keep set
Location	iOS	Turn off location	Easier on iOS
CSLI	Any	Airplane mode	high tradeoff
Stingray	Any	Airplane mode	high tradeoff
	Android	Detection apps