(Image credit: Getty Images) HNLMS Evertsen, a Dutch air-defense frigate part of the NATO carrier strike group centered on the French carrier Charles de Gaulle, has inadvertently revealed its position after receiving a postcard containing a hidden Bluetooth tracker. According to The Register, the Dutch Ministry of Defense posted instructions online to make it easier for family and friends to communicate with personnel aboard a navy ship, but didn’t fully consider the ramifications for operationa...