This type of operation (a kind of self dealing) has sometimes resulted in significant losses for the depositors and constitutes a financial crime. And then there are the more common practices that many individuals face in their lifetime.
The unscrupulous insurance agent or investment fund manager who deliberately promises an unsuspecting client, more than could be delivered; who tells you that your principal is guaranteed when it is not; who tells you that your premiums will never increase when the fine print says otherwise: the insurance company which refuses to pay your claim even though you kept up with your premiums.