WhatsApp
Sorry, your message database has been corrupted.
Sorry, we can’t restore any of the backups.
Sorry, our encryption keys are per-device and rotated aggressively.
Why the fuck do you encrypt your message database? Oh, right, because you’re a closed source piece of shit with a freemium business model, trying to prevent people from voting with their feet.
How many times do I need to re-learn my lesson about using ethical software?