Check this infographic on How US - IRAN secret Cyberwar worked.
After all, Information Technology shouldn't become one danger like Nuclear Technology.
It could, today most systems are computerized and interconnected with networks. Any damage happen will reflect the global economy as the networks expanded with internet.
Today is rebirth of internet protocol with IPV6 launch worldwide. Let's believe and promise we use technology for the good and betterment of humans. At least, definitely not for any destruction.