Somewhat similar damage as happened to a dime I posted up a few days ago. It appears as though something pins the object in the center, leaving it relatively undamaged. Then something rotates against it, sanding away a portion of the coin, that rotating object grabs the coin again, rotating it to a new position, the coin gets lodged, and the process repeats all over again.
Only thing I can think of.
I'll admit, boredom gets us humans to do silly things. If someone is intentionally doing this, wow, there must not be much else to do for sure!
After more closely looking at my sad dime and your penny,
PMD for sure!
Oh, and my dime, after weighing it, it is .15gms lighter than an un-sanded dime.
Enjoy,
RFIII