A peek behind the scenes of RIAA’s anti-piracy efforts from the New Zealand Herald:
To root out illegal file-sharing activity, the RIAA works with Maryland-based MediaSentry, which has developed customized programs that also operate over the Gnutella network. MediaSentry has a list of recordings owned by RIAA-member companies and, like any P2P user, can search for a music file by song title. MediaSentry then collects alphanumeric “hash” codes it discovers online that are associated with these recordings. LimeWire and similar programs will identify how many users are sharing the same file as identified by the hash code. The combination of song titles and hash codes listed in the ever-growing database are the foundation and starting point of all RIAA investigations.