Most security protocols incorporate metal detectors, which could be characterized as "active scanning". By doing so, they release potentially harmful radiation. Repeated exposure, as might be experienced by people who frequent a certain building, may cause lasting damage to our bodies. Instead of emitting radiation, the Passive Portal™ accepts inputs from the world by reading variations in the Earth's magnetic field associated with the presence of ferro-magnetic metals, metals commonly used in weapons. This allows it to alert security staff when firearms, knives, and other weapons are brought into the building.