Burglars & 'fences' don't like marked property. Burglars look for items that they can quickly sell and turn into cash like jewelry, electronics, guns and anything else that might be valuable and of course cash itself. Naturally, burglars don’t want to be caught during a burglary but they also don’t want to be caught afterwards in possession of stolen property. Police can easily identify recovered items as stolen property if they still have a serial number associated with the owner or the items are marked with the owner's unique identifying information. This makes serialized and marked property riskier to possess and less valuable on the street. Because of this, you can deter some burglars if you use decals on your house to make it known that your valuables are marked. Also, marking your valuables make it easier for police to return them to you if recovered and helps our judicial system prosecute burglars who are caught with them.