Back around 2005-2007 or so one of our trucks got broken into and had a couple chainsaws, ropes, climbing gear, etc stolen out of it. Each of the saws had my company name and last 4 of my SSN engraved in the housing under the filter. Nothing else was marked. When I filed a police report with Chesapeake VA PD they took note of the markings on the saws.
Two days later I get a call from the detective who had taken my report. At least in VA if something is stolen that is marked by the owner in a way that can be identified the description of the item and the markings goes out to all local pawn & consignment shops, etc. A pawn shop owner in VA Beach, about 40 miles from where my truck got broke into, had seen that report and when one of the little pricks who broke in our truck tried to pawn one of the saws he saw the markings and called it in.
We wound up getting almost all of our stuff back a couple weeks later. The same guys had been hocking all sorts of other stuff through that same pawn shop and several others for months, but none of it had been marked or had serial numbers that matched any known stolen items until they walked in with my saw. When they searched the thief's parents' houses they also recovered items reported stolen from more than 50 other businesses, vehicles and homes. The paper said the value of items recovered was well over $100,000. The detective said it was likely that none of it would have gotten back to their owners if I hadn't engraved my saws like I did, not to mention how much more stuff they would probably have gotten away with if they weren't caught when they were.