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).

  • Bazoogle@lemmy.worldEnglish
    20·
    11 hours ago

    Not all, no. There are alternatives on Android:

    The good news is that alternative methods for push notifications are available, namely SSE (Server Sent Events) and WebSockets.

    Additionally, a new open source project, UnifiedPush is becoming increasingly popular. UnifiedPush is an open source, private alternative to Google for notifications.

    https://tuta.com/blog/google-push-alternative#alternatives-to-google-push

    Signal for android uses web sockets for notifications