Here is an opportunity to post images of your damaged coins. Here's an example of a piece that I picked up in a dealer's discard box for around $40: http://www.greatcollections.com/Coi...alf-Cent-Crosslet-4-Stems-ANACS-VF-30-Details
Thanks, not much of a distraction IMO. What the grading services call "damaged" for grading purposes usually makes sense, but I have seen a fair number of graded coins that were damaged and were either not caught or considered to be "bad enough". I once picked up an 1874 $20 Liberty that looked MS but had an "Y" right on the cheek of liberty. NGC graded it MS60. My guess is they did not see it as grafitti or "intentional"; so it seems that TPGS' decisions may go to "intentionality", that accidental marks are accepted but if someone did something directly to mark the coin, it no grades. In the case of the half cent I posted, it looks like grafitti to me, but very old. Coin detectives are good at coming up with the original causes of these things.
This Peace dollar was scotch taped inside a birthday card for a long time. I suppose that counts as damage.