2 ex - federal officials say U.S. electrical grid , other countries targeted . Homeland Security does n't report a code , says no deaths caused by one . Department of Homeland Security Director Janet Napolitano would not confirm such a breach , but said Wednesday that there has been no known damage caused by one . ` FBI says this kind of code can be difficult to detect .
2 ex - federal officials say U.S. electrical grid , other countries targeted . Homeland Security does n't report a code , says no deaths caused by one . FBI says this kind of code can be difficult to detect .