One risk facing policy makers is that if the capital injections are seen as a government seal of approval, that could destabilize banks that don't receive investments, causing their customers to jump to other institutions, said Ellen Seidman, a former economic adviser in the Clinton administration.

"It's counterintuitive, but if we've learned one thing from this crisis, it's that we have a hard time predicting the behavior of the smaller savers and investors," said Ms. Seidman, now at the New America Foundation. LINK