Revenge on worldwide company networks in recent months appears to show a direct correlation between IT staff layoffs and internal security breaches.

IT companies are the main target of attacks in the U.S. with the Federal Bureau of Investigation (FBI) issuing a formal warning of a sharp, upward trend in security breaches from disgruntled ex-employees. Although it could not reveal exact numbers, it noted that since the last economic downturn in the early 1990s, the overall work force is more skilled

and employees have greater access to company networks.