secrets from u.s. car makers and chemical companies. chinese hackers are also blamed for attacks on large information systems, including google's networks. it's not known how much has been stolen or at what cost, but reliable estimates put the loss at more than $100 billion a year. in this computer age, cyber espionage is increasingly replacing cloak-and-dagger. >> if you can steal massive amounts of information from other people's networks from halfway around the world, you don't need a spy to penetrate the organization. >> reporter: the new intelligence report warns cyber attacks are going to escalate, calling them, scott, a growing and persistent threat to the u.s. economy's security. >> pelley: bob, what does u.s. intelligence worry the most about with cyber attacks? >> well, they are especially worried about the vulnerability of the nation's electric power grid because, frankly, with a few mouse clicks, the grid could be disrupted, in the worst case even taken down. in fact, brenner told us if at all possible we should try to