I don't post here really often, because normally everyone says what I was thinking and more. I did have one thing to add here that I don't think was touched on directly.
Here is why I bought my UV light. About 10 months ago I had my motorcycle stolen, parted out, and put up on eBay. I had thought before of taking a UV marker and putting a special serial number all over the bike, since the only parts with a VIN are the frame, engine, and transmission. I didn't get around to doing it though, and the situation turned into a real mess trying to prove that the motorcycle was mine. It took a TON of circumstantial evidence and several lies by the seller to get enough for a warrant. It would have been a lot easier if I could have simply told the cops to buy one of the pieces and light it up under UV.
After that happened, I did finally buy a UV light and security marker. My TV, stereo, and anything else of value has a combination of my birthday, SSN, and place of birth that only I will know, and will only make sense to me.
If something like this happens again, it will be a lot easier to point at the TV in the pawn shop and say, "THAT'S MINE!!".