When LimeWire agreed in May to pay $105 million to settle a copyright infringement suit brought by the major music labels, Wired magazine called it “the end of an era.” The era in question, of course, was the roughly decadelong period during which the recording industry litigated aggressively to stop the unlicensed swapping of music online via so-called peer-to-peer networks.

The end of one era, it turns out, means the start of another. Amid an 11-year decline in global sales, the music industry has already turned its attention to what it apparently views as a new threat: cloud-based “music-locker” services launched by Amazon, Inc., Apple Inc., and Google Inc.