Record company investigators have raided universities and internet companies in Australia to look for evidence of online music "piracy".
Kazaa has three to four million users at any one time
The record labels were given permission by the country's Federal Court to swoop on 12 sites across three states.
They were collecting evidence against Kazaa, the world's largest online service for sharing copied songs.
Sydney-based Sharman Networks, which owns Kazaa, called the raids a "knee-jerk reaction" by the music industry.
The Sharman Networks' offices and the homes of two of its executives were raided, along with internet service providers and three universities.
The raids were carried out by a group called Music Industry Piracy Investigations, which is owned by Universal, Festival Mushroom Records, EMI Music, Sony Music, Warner Music Australia and BMG Australia.
The music industry would launch legal action against Kazaa in the country's Federal Court on Tuesday, the group's general manager Michael Speck said.
"This sends a very clear signal to internet pirates in Australia that the game is up," he said.
Kazaa has three to four million users at any one time, and Sharman said it was a "gross misrepresentation" to say the service facilitated or encouraged copyright infringement.
'Waste of time'
In a statement, Sharman said it was complying with the court orders - but would appeal.
The company said the action was "an extraordinary waste of time" by going over the same ground as legal actions in the US and The Netherlands.
In December, the Dutch Supreme Court ruled that Kazaa was a legal operation and did not violate copyrights.
Some of the world's biggest media companies have also taken court action against the service in the US.