This invention relates to a security device, system and method for use in monitoring an object or person, the device being mountable to an object or person and including a tilt sensing means having a tilt sensor and a control means configured and adapted to detect tilt movement of the said object or person and generating an alarm signal when the detected change of tilt movement of the said object or person exceeds a tilt alarm threshold, the change of tilt movement is between a predetermined normal state of alignment of the said object or person relative to a reference plane and the preset threshold level for triggering an alarm signal.