MVS Serial Numbers

I just started collecting MVS games, and received a few in the mail with serial number scratched off. Why do people do this? I didn't buy them for collectibles or anything cause thats not what mvs is for, but I don't understand what the need is to scratch the label.

s4ms0n

I once read that people do this to "erase" a cart's history, so that you can't find who it belong to and such... Anyone else has info on this ?

bump...

that makes sense xonox, anyone else have an idea?