I try to have this mark over some security elements of the card. Anyway, someone wanting to commit a fraud using someone else docs should be able to go over it.
My thinking is that if they have 2 documents and one is clean and another one is mine (demanding some work), maybe they will use the clean one and not mine. I'm probably being naif, anyway.
Another way, not to mitigate, but to try to detect that a fraud was from a prop firms is to use driving license instead of ID card or passport. I never use driving license for anything so if someday a fraud comes with a driving license it's likely to come from a prop firm document sale (although I still won't know which prop firm did it).
Any more ideas are appreciated.
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