Summary:
- This article discusses a tool that can be used to secretly track users of the messaging apps Signal and WhatsApp by monitoring their delivery receipts.
- The tool, called "Reconnaissance," can collect data on when messages are delivered, allowing the user to infer information about the recipient's activity and location.
- This tool raises concerns about privacy and security, as it could be used by malicious actors to monitor and potentially compromise the privacy of messaging app users.