Abstract: One example provides a computing system comprising a case and a wearable device associated with the case, wherein the case is configured to hold the wearable device, and a sensor is located on one of the case and the wearable device. The computing system further comprises a logic subsystem and a storage subsystem. The storage subsystem comprises instructions executable by the logic subsystem to operate the sensor on the one of the case and the wearable device to read an identifier located on the other of the case and the wearable device, compare the identifier with a stored identifier, and when the identifier does not match the stored identifier, then output an alert via an output device.