[Aefiam]

The optimal amount of fraud is zero.

But fraud prevention is not free and has negative returns at some point.

I dislike it when people use "the optimal amount of fraud isnt zero", because it is wrong and makes the underlying problem harder to understand, which is that people like to overoptimize a single desirable property(fraud prevention) without considering other desirable properties(like ease of use and a low rate of false positives for legit transactions)