Memory devices, systems including memory devices, and methods of operating memory devices are described, in which security locks are implemented to control access to secure functions of the memory devices. In one embodiment, the memory device detects a predetermined signal directed to the memory device. The predetermined signals may include one or more commands directed to the memory device, an operating parameter of the memory device, or both. The memory device may track instances of the predetermined signals to compare with a threshold stored in the memory device. If the memory device determines that the predetermined signals satisfy the threshold, the memory device prohibits access to the secure functions.