The popularity of MP3 as a format gave rise to audio file- sharing services on the Internet such as Napster and mp3.com. Some of these services ran afoul of the music and entertainment industries in the late 1990s and early 2000s because they allegedly facilitated unauthorized sharing of copyrighted music. Settlements of the copyright claims were expensive and caused major changes in the file-sharing services, but listeners continued to seek sources of music files while the music industry developed secure ways of selling music to audio consumers.