Peter Stokes allegedly used sophisticated methods to obscure his identity during a breach at a luxury retailer, but the FBI uncovered his identity through a Global Device Identifier (GDID) linked to his Windows installation. GDID is a persistent device-level identifier that uniquely identifies a Windows installation and remains unchanged through operating system updates, only resetting upon complete reinstallation. Users cannot disable GDID, and attempts to remove it may disrupt Windows activation. To minimize data associated with GDID, users can opt for a local account, limit diagnostic telemetry, disable Activity history, and be cautious during reinstallation. VPNs do not prevent Microsoft from logging GDID, IP addresses, and URLs, making them ineffective for privacy on Windows. GDID has been described as a covert tracking beacon, and security experts advise against using Windows for sensitive tasks, suggesting alternatives like Linux.