FBI head: Cyber crime posing 'enormous challenge'

Law enforcement faces an "enormous challenge" in preventing state-sponsored cyber crimes, FBI Director James Comey said Wednesday, days after the Justice Department charged five Chinese military officials with hacking into American companies to steal trade secrets.

"There are two kinds of big companies in the United States: those who've been hacked by the Chinese and those who don't yet know that they've been hacked by the Chinese," Comey told the Senate Judiciary Committee.

"It's a problem," he added, "that we are responding to with a lot of energy, working with a lot of partners across the government."

The increased focus on cyber security has heightened the FBI's demand for new, tech-savvy experts.

Comey, describing efforts to build the FBI workforce, was quoted this week as saying that "some of those kids want to smoke weed on the way to the interview." But he said Wednesday that he had no intention of changing current policy that disqualifies applicants if they've used marijuana in the last three years.