I am aware of at least 2, I'm not in the U.S. , to disclose one crime I'd have to breach confidentiality and the most likely outcome would be that the bank would get a slap in the wrist or even nothing, meanwhile I'd be sued to oblivion and it would ruin my life (the same happens with some other crimes I know about, I once tried an anonymous tip about some grifting in the military and instead of taking it they said they went fully hostile and said they'd trace my call !!).

The other one I didn't have enough proof, apparently someone else did tip the authorities and the shady payday loan company is getting a slap in the wrist. Not exactly something to instill confidence in our justice (and my country is one of the least corrupt ones!)