The 750 suits come just a few days after Internet researchers released a study that found peer-to-peer traffic had remained constant or risen up to the early days of 2004, despite the pressure of recording industry lawsuits.
But the RIAA said its lawsuits were helping build a foundation for the growth in authorized music services such as iTunes, Napster and others.
"In order for legitimate services to continue their growth, we cannot ignore those who take and distribute music illegally," RIAA President Cary Sherman said. "There must be consequences to breaking the law, or illegal downloading will cripple the music community's ability to support itself now or invest in the future."
The music labels' trade association is a little more than a year into its strategy of suing individual file-swappers for copyright infringement, a campaign it hopes will sharply curtail the rate of MP3-swapping on networks such as Kazaa and eDonkey.
The lawsuits have dramatically raised awareness of the legal problems with trading copyrighted files online, and some reports have found steep decreases in the number of people trading music.
A recent study by NPD MusicWatch Digital found that the proportion of MP3 files on people's hard drives, as compared to music formats used by Microsoft or Apple Computer software, was falling. Analysts said that people were still downloading MP3s quickly, but were from their hard drives--possibly a sign of fear over the record industry lawsuits.
The recent peer-to-peer study was written by researchers at the Cooperative Association for Internet Data Analysis at the University of California, San Diego, along with several other universities. It found that a full analysis of peer-to-peer traffic, including protocols that masked themselves as Web traffic or were otherwise difficult to find, found that aggregate file-swapping traffic had not declined between August 2002 and January 2004.
"We find that, if measured accurately, P2P traffic has never declined," the researchers wrote. "Indeed, we have never seen the proportion of P2P traffic (on networks) decrease over time...in any of our data sources."
But the study did find that traffic patterns had shifted. As, the FastTrack network used by Kazaa had decreased substantially, while BitTorrent--a program used widely for very large files such as movies or games, rather than individual songs--had grown considerably.
The RIAA declined to comment on the study.
The latest round of RIAA suits brings the total number of people sued to 6,191. The record industry association also said that it had filed new suits against 213 individuals who had previously been sued as unnamed "John Does," after finding their identities through the litigation process.
The details of that process are still being worked out in some cases. Earlier this month, a court in Philadelphia ruled that the RIAA could issue subpoenas for the identities of anonymous file-swappers, but those people must be notified by their ISP of the RIAA's action within seven days.