The federal database of stolen items is purged of an item when it's been listed for 6 months but still not recovered. I learned that years ago when researching stolen property, looking for the legal owners. Luckily, IBM maintained their own database and I could confirm an electric typewriter (that dates me!) was stolen property.......the serial number had been in the federal database but was purged after 6 months. Firearm serial numbers are never purged as they are kept in a separate, but linked, database.

As for my own weapons; I place one of those "address labels" with my name, address and phone number, under the grip or under the butt stock. I'm not giving away any "personal information" that can't be found in the phone book.