This is a good thing.
This issue was discussed recently on the rec.arts.tv newsgroup. Almost all posters were against such prosecutions and lawsuits because they felt the music industry was "greedy", copyright laws were too strict, or they did not respect the concept and laws of intellectual property (some refused to even recognize the concept). Some claimed the music industry was doing illegal things to sniff out piracy which in fact is technically impossible to do at this time.
I didn't agree with them. I think the concept of intellecutal property is extremely important and inventors, authors, and artists have a right to retain ownership of their works (as provided in the U.S. Constitution).
The music industry is going after high volume pirates, not individual stealing one or two songs. Today's technology makes it possible to easily reproduce and distribute high quality free duplicates of the original in high volumes. This wasn't possible years ago.
As to the issue of U.S. copyright rules being too strict, stealing is not the answer. Those who feel that way should get off their butt and write congress saying so.