1. Yahoo was attacked on Monday, 7 February 2000 for 3 hours, by high rate pinging.
2. Fifty computers of Standford University, California were made inaccessible by DDoS attack by hacker.
3. CBI site was attacked recently by Pakistan Cyber Army.

Every country keeps a Cyber Army of which that of Iran and China are very active in hacking enemy Govt sites.

India has more than 30 million internet users and 217 IT Act related crimes were recorded in 2007.