That is actually a very important question, Gail. I know my Social Security Number and full name is on countless documents. I just recently went through some old Navy documents and took two large boxes to one of those shredder trucks that pop up occasionally at NFCU.
What I had forgotten is that each and every Enlisted Evaluation and Officer Fitness Report used to include the individual's and the reporting senior's full name and Social Security Number. I had saved all of mine (and still have them) and I saved every CPO Eval and Officer FITREP I had ever signed. There were hundreds. I had heard somewhere along the line that I should keep them in case someone filed a grievance. Well, that never happened and I don't think they meant for me to keep them for eternity. I destroyed them all.
But now I wonder - how many former subordinates have my full information stored in "boxes in the attic" and laying around in unsecured and easily accessible locations?
My advice is to get rid of all of that stuff properly. It's not important anyway. If there is some sentimental value to any document at least black out the SSN.