You are right Altamura that there are some but what I meant is that this is a very small number compared to the overall coins for those emperors or the number of times people claim they have one. Normal damage and wear are far more common than actual evidence of DM.
I quite recommend the recent book "Defacing the Past. Damnation and Desecration in Imperial
Rome by Dario
Calomino, project curator in the Department of Coins and Medals at the British Museum, for anyone interested in these coins.
SC