Music stars including rapper Jay-Z and singer Sheryl Crow have welcomed a court ruling allowing record companies to sue illegal file-sharing firms.
Rap star Jay-Z has welcomed the court ruling
Jay-Z called the US Supreme Court's decision a "great victory" for those who "make their living through the creative process".
The surprise ruling could start a legal assault on the creators of file-sharing networks such as Morpheus.
But some artists said it could stifle their online career development.
Eagles star Don Henley, president and co-founder of the Recording Artists Coalition, said that file-sharers make millions in adverstising revenue but give nothing to artists.
Henley and 53 other artists - including Tom Jones, Bonnie Raitt and the Dixie Chicks - signed a legal motion in support of record companies.
Raitt said: "We fully embrace P2P technology. But artists must have a choice between systems offering music for free and systems that pay us."
Natalie Maines of the Dixie Chicks said the ruling would give fans easier access to "legitimate sources of music".
But singer-songwriter Janis Ian said the move would make it harder for new bands to gain a foothold in the industry.
"This is going to cut off a lot of avenues, especially for start-up bands," she said.
The singer does not use using file-sharing software to circulate her music, but gives away some music free on her website.