The Dow Jones Industrial Average (DJINDICES:^DJI) fell 0.2% today, while the broader S&P 500 (SNPINDEX:^GSPC) declined 0.3%. Let's take a look at moved the markets.

The Justice Department announced today that it's suing Dow component Bank of America (NYSE:BAC) for $1 billion for selling bad mortgages to Fannie Mae and Freddie Mac. Earlier this month, the U.S. already filed lawsuits against two of the bank's peers, JPMorgan Chase (NYSE:JPM) and Wells Fargo (NYSE:WFC).

Last week, in our roundtable discussion, "Is Bank of America Now a Buy?," I noted that B of A's "third-quarter results are emblematic of why investors are still reluctant to buy the shares of the top few banks, and those who are will pay only depressed multiples for the equity. ... [T]his financial crisis is more resilient than Jason Voorhees as far as bank losses are concerned."

Clearly, one would have to be insane to buy bank shares now -- insane like Berkshire Hathaway CEO Warren Buffett, who told CNBC this morning that he's been buying shares of Wells Fargo over the past week. While he recognizes that pre-crisis levels of profitability are no longer viable, he thinks banks are "still a good business."

In concluding my roundtable contribution last week, I wrote:

Once the regulatory burden on banks is widely understood and it is widely accepted that no substantial crisis-related losses remain, no possibility of earning an above-market return will remain, either. At close to a 30% discount to tangible book value, B of A shares look, at first glance, like they offer investors a healthy margin of safety in compensation for bearing this uncertainty and the volatility the shares could exhibit on the way to delivering healthy returns.

Even as B of A now faces a new $1 billion potential liability, I stand by that today. If you want to find out which among banks are The Stocks That Only the Smartest Investors Are Buying (including Buffett), click here to request your free report now.