Short answers, pulled from the story.
The word bootleg originates from the practice of smuggling illicit items in the legs of tall boots, particularly the smuggling of alcohol during the American Prohibition era. This term has evolved to refer to any illegal or illicit product and now serves as an umbrella term for unlicensed audio and video recordings.
Bob Dylan's Great White Wonder became the first popular rock music bootleg when it was released in July 1969 using low-priority pressing plants. Bootleggers convinced a local plant to press between 1,000 and 2,000 copies discreetly while paying in cash and avoiding real names or addresses.
By the late 1990s digital file formats like MP3 and Real Audio combined with internet sharing capabilities made it simpler for collectors to exchange bootlegs freely. Older analog recordings converted to digital format while tracks from bootleg CDs ripped to computer hard disks enabled new material creation through various digital recording types.
Federal law prohibited bootlegs since introduction of Uruguay Round Agreements Act in 1994 alongside state laws applying before and after passage. A 2004 court case challenged constitutionality when Judge Harold Baer Jr struck down part banning sale of live music bootleg recordings claiming unfair perpetual copyright periods.
Frank Zappa hated bootlegs wishing to control his recordings so he created Beat the Boots boxed sets containing direct copies of existing bootlegs. He set up hotlines for fans reporting bootlegs yet remained frustrated FBI showed no interest prosecuting.