TLDR: signal content in Apple notification can be retrieved even after signal app deletion.
I saw from this reddit thread: Signal messages retrieved from iPhone after uninstalling app. : signal
Referencing this news article: Pretti Killing May Affect ICE Prairieland “Antifa Cell” Terrorism Trial
The mention of signal is in court documents here: March 10: Federal Trial Day 12 - Support the Prairieland Defendants
Signal chat evidence from Sharp’s device (Exhibit 158):
Messages were recovered from Sharp’s phone through Apple’s internal notification storage — Signal had been removed, but incoming notifications were preserved in internal memory. Only incoming messages were captured (no outgoing).
This is not always the same on Android. Any app from FDroid will not use Google’s push notification service because it is proprietary, meaning it violates the rules for FDroid. Signal does not use Google’s notification service
It’s not because of push notifications. the message is not sent to firebase, just a signal that the app should do a refresh.
It’s because the system saves the notifications apps posted to the notification menu.
Is is 100% because of firebase. Here is an example payload from firebases official document:
{ "message":{ "token":"bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...", "notification":{ "title":"Portugal vs. Denmark", "body":"great match!" } } }https://firebase.google.com/docs/cloud-messaging/customize-messages/set-message-type
Notification history is purely local to the device. It is not sent to any servers.
Yes the notifications were retrieved from the phones local storage. Firebase was not involved in anyway.