While 2 Live Crew is arguably best remembered for their on-stage antics and contentious court battle against obscenity charges, the Miami-based hip-hop group actually played a vital part in creating the Internet we know today—even if they didn't realize it at the time.
The group's parody of Roy Orbison's "Pretty Woman" landed 2 Live Crew in hot water with Acuff-Rose Music, the original song's copyright holder. See, 2LC's manager had reached out to Acuff-Rose for a license to sample Orbison's rock ballad, but was promptly rebuffed. Regardless, the band recorded and released their parody, selling nearly a quarter million copies before Acuff-Rose sued them a year later for copyright infringement.
The resulting lawsuit—which first saw a district court find in favor of 2LC only to be overturned on appeals due to it being a commercial parody—eventually wound up being argued before the US Supreme Court. 20 years ago today, the justices ruled in favor of 2LC, arguing that the parody was protected by fair use despite being a commercial venture. According to the court, the "more transformative the new work, the less will be the significance of other factors, like commercialism, that may weigh against a finding of fair use." This set the precedent that while commercial use was certainly a factor in determining whether a derivative work qualified for fair use protections, it was not the only—or even the primary—determinant and carried less weight the further a derivative work veered from the original.
This ruling has subsequently affected the development of mass media while strengthening fair use copyright protections. Without it, content like The Daily Show, Not Another Teen Movie, Go the Fuck to Sleep, Funny or Die, and similar for-profit parodies likely would not exist. [Tech Dirt - Wiki]