Hip-hop’s commercial power and success, penetrating even the least forgiving corners of the mainstream, seemed to ensure that the old stigma and disapproval had all but vanished. (The same goes for the old accusation that hip-hop artists sold out by partnering with big corporations that held purportedly opposing values — hip-hop took those contradictions and made them into art.) In this environment rappers looked like safer bets than ever for corporate endorsements: widely known and admired, with a frisson of counterculture still stuck to them. They are outsiders recognizable to insiders, and far better celebrities than the generally faceless titans of dance music or the declining stars of rock.

And yet those old debates have returned with a vengeance in recent weeks, re-energized by the frictionless way social media can speed up conversations. In each instance it was only days between the identification of the offense and the end of the business relationship. In the case of Mr. Ross and Lil Wayne the intense criticism was justified. Mr. Ross alluded to nonconsensual sex with a woman, using slang for Ecstasy, in his verse on Rocko’s “U.O.E.N.O.”: “Put molly all in her Champagne, she ain’t even know it/I took her home and I enjoyed that/she ain’t even know it.” Lil Wayne, on his verse in the remix of Future’s “Karate Chop,” invoked Till as part of an explicit sexual simile. (In each situation the offending verse was part of another artist’s song and therefore might have been policed less vigilantly than if it had been on Mr. Ross’s or Lil Wayne’s own album.)

Mr. Ross’s lyric is reprehensible; Lil Wayne’s is regrettable and tacky. (Lil Wayne is by no means the only rapper to mention Emmett Till in song, but his use is easily the messiest.) Both men issued tepid nonapologies. Mr. Ross eventually progressed to a full apology, but only after prodding.

In each case justice was swift, as companies said, rightly, that their values didn’t jibe with the sentiments of those lyrics — and, by extension, those artists.