Mass layoffs are painful events for employees and employers alike. But for employers, increasingly more than just personnel are leaving their facilities: researchers estimate that data theft cost businesses $1 trillion in 2008.

In a recent study commissioned by McAfee, Inc., researchers at Purdue University's Center for Education and Research in Information Assurance and Security (CERIAS) polled 800 executives at businesses with more than $250 million in annual sales. Of the executives surveyed, 42 percent said that laid off workers were the biggest threat to business caused by the current recession. Businesses reported losing $4.6 million on average in 2008 as a result of data theft. McAfee noted that a lot of anecdotal evidence shows that many of the thefts were internal.