Documents published by The Intercept reveal the scope of information that US authorities can obtain from Apple's iMessage messaging service (now renamed Message) through court orders.
Because all iMessage content is end-to-end encrypted, not even Apple itself can access the actual conversations. However, iMessage messages also contain some metadata that is sent and stored on Apple's servers.
For example, Apple records every new conversation that users attempt to start. Every time a user enters a person's phone number through the app, iMessage sends the information to Apple's servers to determine whether the other number also belongs to a user who has the iMessage app. This information is used before starting each conversation via iMessage or the phone's default SMS app.
Thus, authorities that have court decisions, using this data, can discover who a user has spoken to, the date, time, and IP address.
Metadata does not necessarily indicate that a conversation took place, but it certainly indicates that the user at least attempted to communicate with the other party.
Furthermore, because the data stored also records the user's IP, the Authorities or someone else can determine the user's geographical location based on their IP.
Apple apparently lied about not storing such data in 2013 when Edward Snowden first revealed the NSA scandal. At the time, he revealed that Apple was allowing the NSA to collect metadata from its service.
In a statement following Snowden's revelations, the company said that "we do not store data about customer location, map searches, or Siri requests in any identifiable form."
The documents published by The Intercept are called “iMessage FAQ for Law Enforcement,” and are a kind of manual detailing what kind of data Apple can collect. The files clearly show that Apple collects location information in the form of IP, contrary to previous statements from the company.
