Last week investors in mortgage securities, including the Federal Reserve Bank of New York, sent a letter to the Bank of America, demanding that it buy back billions of dollars of mortgages that were bundled into securities and sold by Countrywide. (Bank of America took over Countrywide in 2008). Investors contention is that the documentation supporting the loan is faulty, and that Bank of America did not correct the deficiencies in the loan files and lien records when these deficiencies were found. Investors can try to force a bank to buy back its securities, if the strict rules governing the issue of such securities were not followed. As the market for mortgage securities is about $1.4 trillion dollars, even if a small fraction of the securities is affected, it would pose serious problems for the banks. This is a problem that can't be papered over.