A Bluetooth tracking device, valued at around $5 (Rs 460), was cleverly hidden inside a postcard sent to the Dutch warship HNLMS Evertsen on March 27. This tracker transmitted the ship's location for nearly 24 hours by utilizing the crew's nearby phones, leading to a significant security breach. The HNLMS Evertsen, worth approximately $585 million, is part of a NATO group led by the French aircraft carrier Charles de Gaulle. The Dutch defense ministry had previously shared mailing details online to keep families connected with deployed personnel, inadvertently creating a vulnerability. Following the discovery of the tracker during routine mail sorting, Dutch authorities acted swiftly to ban electronic greeting cards to prevent similar incidents. Former Lieutenant General Mart de Kruif emphasized the need for a shift in mindset regarding security protocols, stating that actions should be based on necessity rather than existing rules. This incident follows a pattern of security lapses in naval operations, including a similar event involving the US Navy ship USS Manchester and a French officer's location sharing on the Strava app.