Not at all, Fairy. I have known people who have had their harps (and cars) removed at gun point. The average thief-type person knows nothing about serial numbers and is not going to fence it to anyone who does, either.
L&H once told me they had gotten back a gold harp that had been stolen, and the thieves had sawed the column into pieces, thinking it was all gold. They were disappointed.
Also, I have known of harpists stealing harps, too. There are a few people out there who have to stay out of certain countries now.