I have always wondered why people want to keep their serial number from being seen when posting a picture. Now if it were obtained in a not so legal way that would be one reason. What other reasons would there be?
Traditionally it was to avoid bringing drama into one's life with the possibility of someone claiming "That's my gun, it was stolen from me." Now I think it's more out of habit or people thinking it's something they should do without really knowing why.
I think what a as said is true and very reasonable. But how realistic is it? For example I'm here in the great state of Texas. If I show a gun and Cholo over in Georgia says hey that's my gun and here's the serial number. Well doesn't he need more proof than the number? And being so far away? I guess if a lawyer gets involved and starts muddling everything up...