As it is, one of the biggest threats to corporate data and systems traditionally has come from insiders, who with their privileged access to data and systems, have the potential ability do more accidental or malicious damage than even the outside attacker.

That threat greatly increases at times when companies are laying off staff, cutting back on raises and bonuses, deferring promotions, consolidating operations and outsourcing work to save money.

"All of these increase risk for the company from an insider perspective," said Shelley Kirkpatrick, director of assessment services at Management Concepts, a Vienna, Va.-based management consultancy.

Tough economic times create uncertainty in the workplace, she said. Employees for instance, can be worried about losing jobs and promotions, concerned about financial liabilities, mortgages and rising energy costs. "When there is uncertainty, it creates stress for employees. It makes the company more vulnerable" to threats, said Kirkpatrick, who was previously a behavioral threat assessment researcher at the Homeland Security Institute.

The threats can manifest themselves in a number of ways. Insiders with access to corporate information, such as customer data or corporate secrets, might want to steal or disclose it for financial gain or simply to get back at their companies. Those with technical- savvy might seek to sabotage corporate data and systems by planting malicious code and so-called logic bombs that are designed to delete data at a future date on critical systems.

The danger is not confined to such actions alone. Stressed, unhappy workers make easy targets for opportunistic rivals as well, Kirkpatrick said. "If I am a competitor looking for a good opportunity to get trade secrets out of my competition, I am going to go after the people who may be stressed emotionally," she said.

Examples of insider sabotage

The damage that insiders with privileged access can do should not be underestimated as several incidents in the past show, analysts said. In July, for instance, a disgruntled administrator for the city of San Francisco locked access to a critical network by resetting administrative passwords to its switches and routers and then refusing to divulge them to officials for days.

In a similar incident, a Unix systems administrator at Medco Health Solutions Inc. who was concerned about being laid off, planted a logic bomb on an internal system that, had it gone off, would have deleted data on 70 servers.