The top U.S. intelligence official says cyberterrorism is the leading worldwide threat to U.S. security.

James Clapper is director of national intelligence.�He’s telling Congress Thursday that cyberattacks and cyberspying can damage critical infrastructure like power grids. But in prepared testimony, he says advanced cyber-actors like Russia and China are unlikely to launch such attacks unless they are threatened by conflict.

He gives examples like last year’s denial-of-service attacks on websites for U.S. financial institutions, and the attack against 30,000 computers at Saudi oil company Aramco, as typical of what’s to come.

Clapper also says al-Qaida and its offshoots will continue to plot attacks on U.S. targets. He warns that the Arab Spring revolt has produced a spike in threats, and that Iran continues to present a danger.

(AP)