In recent years, many banks have gone bankrupt. This is due to their inability to deal with the financial crisis and even their own mismanagement. Many depositors do not get their money back because of these failures.
This is because the Federal Deposit Insurance Corporation (FDIC) will only cover up to $250,000 in deposits per bank per account holder. In other words, if you have more than $250,000 in the bank and it fails, you're out of luck.
This is a problem for depositors who deposit their money in bankrupt banks because they do not want to lose the money they have already lost. But what makes matters worse is that FDIC regulations don't allow them to keep their money even if they can get it back from another bank or institution.