To be fair, isn’t that the actual law? Last sentence of below:
The Federal Deposit Insurance Corporation Improvement Act was passed in 1991, giving the FDIC the responsibility to rescue an insolvent bank by the least costly method. The Act had the implicit goal of eliminating the widespread belief among depositors that a loss of depositors and bondholders will be prevented for large banks. However, the Act included an exception in cases of systemic risk, subject to the approval of two-thirds of the FDIC Board of Directors, the Federal Reserve Board of Governors, and the Treasury Secretary.[26]