The Irish Recorded Music Association (Irma) is seeking damages and injunctions against 50 individuals or companies as part of of its legal action against "serial file-sharers" in Ireland.
Serial file-sharers are people who have illegally uploaded hundreds or thousands of music tracks onto peer-to-peer file-sharing networks.
File-sharing networks such as FastTrack - on which Kazaa runs - and Gnutella enable people to link their computers together via the Internet to share the music files stored on their machines.
Last April Irma began its first phase of legal action against 17 illegal file-sharers. The association has settled with 12, at an average of €2,500; is suing three; and is considering legal options in the two remaining cases.
The Internet account holders who agreed to settle included parents, who have admitted liability on behalf of their children, and at least one firm that did not know that one of its employees was using its network to illegally upload music.
Irma director general Dick Doyle
According to Irma, the second phase of legal action is aimed at deterring the illegals and giving crucial breathing space to legal downloading services, and allowing them further room to develop their customer services.
There are six major legitimate services in Ireland: iTunes, Eircom Music Club, mycoke.com, vitaminic.com music club, wippit.co.uk and Sony Connect.
Irma director general Dick Doyle said: "Despite our original legal actions and the press coverage involved with same, it is clear to us that some people are still prepared to act illegally and in a persistent manner."
"Irma must protect its members' interests by taking on file sharers who refuse to get the message," he added.
The International Federation of the Phonographic Industry ítoday announced a total of 2,000 new legal actions in 16 countries in Europe and Asia.