D600 and D7000 shutter scratch - another reason for spots?

Just checked.....D600 serial number starts with 302 very very light scratches. could barely see them without tilting several times in light. Also checked my d7000. That camera was bought in march and it has the scratches. A little more noticeable compared to the d600 but still very light. You would really have to go looking for it to notice it.