The always-insightful Herb Greenberg raises an interesting point in his latest Weekend Investor column for the Wall Street Journal: "Face it: Nobody cares much about accounting scandals anymore."

He uses the situation at International Rectifier (NYSE: IRF) as an example. After the company reported that it had fired its chief financial officer, the stock went up. The shares are currently trading at about the same price they were at before the company reported "accounting irregularities" on April 9.

Investors may have be correctly predicting that the accounting issues aren't huge -- any restatement of earnings may not be material enough to effect the value of the company.

But that's not really the point. As Greenberg writes, "Still, the market's indifference to possible fraud, no matter the size, is astounding -- especially since, at times, aggressive behavior reflects a company's culture."

Now that is precisely the point. I'm with Jim Cramer on this one: When a company's CEO or CFO resigns unexpectedly, sell the stock. If a company announces "accounting irregularities" and the stock doesn't tank on the news, take it as an opportunity to get out: Shooting first and asking questions later would have saved investors a lot of pain at companies like Enron, WorldCom, and, for you history buffs out there, Zzzz Best and Crazy Eddie.

The market appears to have developed an indifference to early warning signs of fraud, and that inefficiency could provide savvy investors with a chance to hop off the bus before it heads into a ditch.