這次 WWDC 推出的新功能，已經有人在討論機制與隱私問題了：「How does Apple (privately) find your offline devices?」。
前一代的「Find my iPhone」需要透過網路與 GPS 資料才能在系統上看到，這一代則是加上 BLE beacon，然後任何一台 iOS device 收到後就回傳回給蘋果：
Every active iPhone will continuously monitor for BLE beacon messages that might be coming from a lost device. When it picks up one of these signals, the participating phone tags the data with its own current GPS location; then it sends the whole package up to Apple’s servers.
幾個隱私問題在於，代傳的 iOS device 也會暴露位置資訊給蘋果，另外收到 BLE beacon 的 iOS device 本身是否可以解讀遺失機器的資訊？而商家看起來也可以利用這個方式主動發送攻擊而得知不少資料 (像是文章裡提到先前蘋果透過 randomize mac address 加強隱私的問題，這邊又多開了一個洞)，現在蘋果給的資訊還不夠清楚，需要真的逆向工程確認才知道...