Panetta: Cyberattacks are every bit as real as terrorism, nuclear weapons proliferation and the turmoil that we see in the Middle East. Panetta says a cyberattack perpetrated by nation states or violent extremists’ groups could be as destructive as the terrorist attack on 9/11. The most destructive scenarios involve cyber actors launching several attacks on our critical infrastructure at one time, in combination with a physical attack on our country. The collective result of these kinds of attacks could be a “cyber Pearl Harbor””]
Source: https://www.cuinfosecurity.com/in-his-own-words-panetta-on-cyberthreats-a-5196