A professor of business at the University of California has written about a number of incidents where technology clashed with copyright in the past century, showing how the battles evolve.

As well as describing what happened in the often discussed Sony verses Universal City Studios case, he explains that in the early 1900's songwriters challenged the manufacturers of player piano rolls over the copyright of the music they were recording, but failed to win a Supreme Court battle.

The result of the win was that Congress devised new legislation on the issue; the Copyright Act of 1909 created a new form of intellectual property, mechanical reproduction rights. This meant that piano roll manufacturers had to pay songwriters a fee for each song.

Mechanical reproduction fees were then extended to cover new technologies like phonographs, audio tapes, CD's and now online streaming digital music.

Concluding the article in the New York Times, Hal Varian writes: "Encourage technologies that create more total value. Then, let companies fight to find business models that deliver that value to consumers. They can be awfully creative when they are forced to be."