Hacking involves illegally accessing computer systems or networks. There are different types of hackers, including white hats who test security, black hats who hack with malicious intent, and grey hats who sometimes help for a fee. Common hacking techniques are password cracking, viruses, Trojan horses, and keyloggers. The Computer Fraud and Abuse Act of 1984 made hacking illegal but some argue it is too broad. Famous hackers include Adrian Lamo and Jonathan James who were black hats, and Wozniak and Berners-Lee who were white hats. The Stuxnet virus targeted Iran's nuclear facilities. Anonymous is a hacking group known for hacktivism. Major hacking events include the "I Love You" virus of 2000