According to Rob Glaser, CEO of Real Networks, "about half the music on iPods is music obtained illegitimately." Glaser's comments were made in an interview with The Guardian where he goes on to discuss why he feels his company is trailing Apple and what Real's strategy is to improve its standing in the digital downloading market.
The average number of songs sold for the iPod is 25, and there are many more songs on iPods than 25. About half the music on iPods is music obtained illegitimately either from an illegal peer-to-peer networks or from ripping friends' CDs, which is illegal.
This is not the first case Glaser has been at odds with Apple or its products. Real drew Apple's fire when they created a technology called "Harmony" in 2004 that allowed Real to sell iPod compatible songs through their music store. Apple later disabled the compatability, and slammed Real for "adopting the tactics and ethics of a hacker."