"Value investing" or "growth investing" are easy to define. But socially responsible investing, which shuns sinful stocks, can be a more slippery concept. After all, what you call a "sin stock" may seem just fine to another investor. To keep pace with changing times, we'd like to suggest another kind of stock that socially responsible investors might want to snub.

The changing face of vice
Some traditional sin stocks are no-brainers. Altria (NYSE: MO) profits from selling unhealthy, addictive cigarettes, which many opponents argue have vast social costs. And if you're ethically opposed to war and militarism, Raytheon (NYSE: RTN) probably isn't up your alley.

However, the aftermath of the financial crisis has earned another segment a spot on some investors' ethical spit list. The Associated Press recently reported that the socially responsible Appleseed Fund recently added a new category to avoid: "too big to fail" banks like Bank of America (NYSE: BAC), Citigroup (NYSE: C), Goldman Sachs (NYSE: GS), JP Morgan Chase (NYSE: JPM), or Morgan Stanley (NYSE: MS).

Bad banks! No biscuit!
The Appleseed Fund makes a good, valid point here. We've all been forced to pay for many big financial companies' poor decisions, in myriad ways. The banks had privatized profits and socialized losses, which hardly sounds "socially responsible" to me.

More importantly, those systemic problems haven't gone anywhere. Congressional Oversight Panel Chairwoman Elizabeth Warren has butted heads with Treasury Secretary Timothy Geithner, arguing that neither the banks at fault nor the government charged with the cleanup have fixed the problems that caused the financial crisis to begin with. Without the government's help, Warren does not believe that the banks are truly sound.

The big banks' involvement with derivatives also figured into The Appleseed Fund's decision. The fund cited Warren Buffett's description of derivatives as "financial weapons of mass destruction." (Perhaps these banks aren't too dissimilar from military contractors after all!)

Let's face it: In any economic bubble, greed tends to overtake everyone. Speculative consumers who decided to gamble on the housing-market casino definitely share part of the blame for the ensuing disaster. But the banks certainly played a huge part in paving our road to economic hell -- with or without good intentions.

Some stocks are worth shunning
I decided a long time ago that the big banks occupied my own personal "shun list." I'd rather search for good, ethical, well-run companies. I was never convinced the big banks' problems were really fixed, even with a massive government assist. And I fear they'll still sell us all down the river the first chance they get. My heartfelt wish in 2008 was to see them fail. The way a lot of their executives whined and grubbed and finagled for bonuses they didn't really deserve made me ill, quite frankly.

Many investors aren't interested in socially responsible investing. Still, I hope they'll at least give a few minutes' thought to what really motivates the companies with which they align their financial interests. After the last couple of years, I'd say everyone could stand to do a little stock-related soul-searching.

Do the big banks deserve the vice stock status or not? Bare your soul in the comment box below.

Check back at Fool.com every Wednesday and Friday for Alyce Lomax's columns on corporate governance.

Alyce Lomax does not own shares of any of the companies mentioned. The Fool has a disclosure policy. Try any of our Foolish newsletters free for 30 days.