A federal grand jury indicts Cornell University student Robert T. Morris, Jr. for releasing the Morris worm, thus becoming the first person to be prosecuted under the 1986 Computer Fraud and Abuse Act.

The Computer Fraud and Abuse Act of 1986 (CFAA) is a United States cybersecurity bill that was enacted in 1986 as an amendment to existing computer fraud law (18 U.S.C. § 1030), which had been included in the Comprehensive Crime Control Act of 1984. The law prohibits accessing a computer without authorization, or in excess of authorization. Prior to computer-specific criminal laws, computer crimes were prosecuted as mail and wire fraud, but the applying law was often insufficient.The original 1984 bill was enacted in response to concern that computer-related crimes might go unpunished. The House Committee Report to the original computer crime bill characterized the 1983 techno-thriller film WarGamesin which a young teenager (played by Matthew Broderick) from Seattle breaks into a U.S. military supercomputer programmed to predict possible outcomes of nuclear war and unwittingly almost starts World War IIIas "a realistic representation of the automatic dialing and access capabilities of the personal computer."The CFAA was written to extend existing tort law to intangible property, while, in theory, limiting federal jurisdiction to cases "with a compelling federal interesti.e., where computers of the federal government or certain financial institutions are involved or where the crime itself is interstate in nature.", but its broad definitions have spilled over into contract law. (see "Protected Computer", below). In addition to amending a number of the provisions in the original section 1030, the CFAA also criminalized additional computer-related acts. Provisions addressed the distribution of malicious code and denial-of-service attacks. Congress also included in the CFAA a provision criminalizing trafficking in passwords and similar items.Since then, the Act has been amended a number of timesin 1989, 1994, 1996, in 2001 by the USA PATRIOT Act, 2002, and in 2008 by the Identity Theft Enforcement and Restitution Act. With each amendment of the law, the types of conduct that fell within its reach were extended.

In January 2015, then-President Barack Obama proposed expanding the CFAA and the RICO Act in his Modernizing Law Enforcement Authorities to Combat Cyber Crime proposal. DEF CON organizer and Cloudflare researcher Marc Rogers, Senator Ron Wyden, and Representative Zoe Lofgren have stated opposition to this on the grounds it will make many regular Internet activities illegal, and moves further away from what they were trying to accomplish with Aaron's Law.

A grand jury is a jury—a group of citizens—empowered by law to conduct legal proceedings, investigate potential criminal conduct, and determine whether criminal charges should be brought. A grand jury may subpoena physical evidence or a person to testify. A grand jury is separate from the courts, which do not preside over its functioning.Originating in England during the Middle Ages, grand juries are only retained in two countries, the United States and Liberia. Other common law jurisdictions formerly employed them, and most others now employ a different procedure that does not involve a jury: a preliminary hearing. Grand juries perform both accusatory and investigatory functions. The investigatory functions of grand juries include obtaining and reviewing documents and other evidence, and hearing sworn testimonies of witnesses who appear before it; the accusatory function determines whether there is probable cause to believe that one or more persons committed a particular offense within the venue of a district court.

In Ireland, they also functioned as local government authorities. In Japan, the Law of July 12, 1948, created the Kensatsu Shinsakai (Prosecutorial Review Commission or PRC system), inspired by the American system.The grand jury is so named because traditionally it has more jurors than a trial jury, sometimes called a petit jury (from the French word petit meaning "small"). A grand jury in the United States is usually composed of 16 to 23 citizens, though in Virginia it has fewer members for regular or special grand juries.