Since last Monday, the RIAA has sent out 75 legal notices to between 40 and 50 ISPs across the US that host file-swapping servers used in a similar way to Napster, but which are not affiliated with the company.
"We believe there are about 80 or 90 'Open Nap' servers in the country, and we're sending these letters out on a rolling basis," Whitehead said. Open Nap servers use software that allows them to perform a similar function to Napster's music exchange service.
So far, the RIAA has been satisfied with the response from those ISPs. "Every ISP I've spoken to has told me that they would take action concerning these servers, and we've seen a couple of them shut down over the past few days," according to Whitehead.
The letters the RIAA is sending out have "given (the ISPs) an opportunity to avoid potential liability," he added.
The weapon the RIAA is using in this battle is a 1998 law called the Digital Millennial Copyright Act, which states that an ISP must block access to any customer upon notification that they are infringing copyrights.
The RIAA plans to send letters to every ISP in the US that it believes is running Open Nap servers. Outside of the US it will need to rely on the International Federation of the Phonographic Industry (AFPI), Whitehead said. "They are fully aware of these Open Nap servers," he said. "International action will take place in due time."
Making matters complicated for the RIAA is Gnutella, a file-sharing system that doesn't rely on central servers, making it more difficult to shut down in court. The RIAA would not comment on Gnutella.