After a letter to DOJ by senator Ron Wyden Apple confirmed that governments were requesting push notification data to surveil users.
"In this case, the federal government prohibited us from sharing any information," the company said in a statement. "Now that this method has become public we are updating our transparency reporting to detail these kinds of requests."
MacRumors
Push notification statistics was used to match Apple ID with patterns of notifications for specific apps (for example, messaging apps). If app uses end-to-end encryption, contents of the messages could not be read by governments, but it is still possible to identify specific users by usage patterns.
Both Apple and Google were providing this data to governments.
References:
- Apple Confirms Governments Using Push Notifications to Surveil Users
- Apple reveals ‘push notification spying’ by foreign governments, after open letter
- Senator's paranoia opens door for Apple to speak out on government censorship
- Governments Using Push Notifications to Surveil Users
- Senator Ron Wyden: Governments Are Spying on Apple and Google Users Through Push Notifications
- Apple Requires Only a Subpoena to Turn Over Push Notification Tokens to Law Enforcement; Google Requires a Court Order
- Apple Adds Push Notification Data to Law Enforcement Guidelines
- Apple updates legal process documents to acknowledge push notification data requests