Nonsense. The copyright belongs to the copyright holder. I know GS like to steal every fucking thing in sight but claiming copyright on a piece of Free Software just because its received a copy is a new low.
Wait I think we are getting confused here. What code are we talking about here.
Copyright of code belongs to the author of the code, or a company that employs him.
If they took say GCC and then replace copyright notices on it, it doesn't become their code, they are using it under a license from the original authors. Replacing a header in a file doesn't magically give you complete control and copyright over it. That would be silly and it would nullify most of the open source software licenses.