One thing to do is an internet search from time to time keying in the serial number of the body, lenses, etc. Not all sites dump metadata when an image is posted and your gear just might show up in a search. It has happened to others and is useful in tracking image use so can be useful to find your gear over time.
If you do so and a search shows images from the serial numbers contact law enforcement first rather than the individual. Getting visited by cops carries a lot more weight than if you make contact.