On Friday, attorneys representing the Knack's Doug Fieger and Berton Averre — songwriters of the 1979 chart-topping hit "My Sharona" — filed a copyright-infringement lawsuit in Los Angeles against the members of Run-DMC, claiming the rappers did not have permission to sample the song's core riff in one of their most recognizable tracks, "It's Tricky."

The filing — which also names Rick Rubin (who produced the cut for 1986's Raising Hell), Arista Records, Rush Groove Music, Rush Communications, online music retailers Yahoo, Amazon, Napster, iTunes and others as defendants — claims that Run-DMC engaged in the "unauthorized copying, reproduction and distribution of [the Knack's] musical composition and improperly [profiting from]" use of the sample, which the suit claims was "willfully, or with reckless disregard, unlawfully appropriated."

The document asserts that, because of Run-DMC's sampling of "My Sharona," Fieger and Averre have "suffered actual damages, including lost profits, lost opportunities, loss of goodwill, lost publicity, attorneys' fees and interest." The suit seeks unspecified damages and related legal fees, and characterizes the "signature" riff sampled in "It's Tricky" as "the essence" of the song.

In addition, the suit requests a permanent injunction barring the sale, reproduction, and commercial release of "It's Tricky," and suggests that Fieger or Averre's "percentage of ownership in ['It's Tricky']" be determined and factored into a declaratory judgment — which should also consider what profits the pair are due from the sale of the Run-DMC song.

"Our clients created a unique and distinctive musical composition in 'My Sharona,' " attorney Dick Schultz said. "Others shouldn't be allowed to profit from the unauthorized use of that creation. That is what copyright laws are for, and we are protecting our clients' rights in their creation."

"That [riff] is not only the essence of 'My Sharona,' it is one of the most recognizable sounds in rock and roll," said Fieger through his lawyers.

Despite the popularity of the riff, some may wonder why Fieger and Averre waited two decades to take action against the hip-hop icons. The lawsuit claims the pair never heard the DMC classic before 2005.

No date has been set for the first hearing in the action. Representatives for Run-DMC were unavailable for comment at press time.