https://www.washingtonpost.com/technology/2019/05/28/its-middle-night-do-you-know-who-your-iphone-is-talking/
(may be paywalled but it was widely reported elsewhere).
Strangely this article about iPhones sending tracking information via background app refresh from May 28 appeared again in my News app this morning dated June 10. It’s the exact same article as far as I can see. It’s pretty shocking that the iPhone had 5,400 trackers sending 1.5GB of data in a month - could be wasting a good percentage of your data plan, never mind selling your soul to the ad tracking companies. The article made a disappointingly small wave in the tide of Apple-specific tech news. I really hope Apple speaks up about this and does something to plug this vulnerability. For now I have turned off background app refresh.
The article recommends that we download and use at least the free version of Privacy Pro. Does anyone have any experience with this app to relate?