Sounds like a great way to strongly incentivize a new form of fraud--fraud-reporting fraud! Imagine how much fraudsters could gain by reporting thousands or tens of thousands of "fraud" calls that they themselves both originate and report from existing SIM farm infrastructure. Any deployment weakness or hole in blocking malicious traffic in the global telecommunications network all of the sudden becomes akin to a weak smart contract that is ripe for exploitation on the order of millions of dollars of fines until it is patched, all due to this depositing requirement.