The cat and mouse game between the recording industry and the public peer-to-peer networks has spun around again with StreamCast Networks adding an anonymizer feature to its popular Morpheus service.

The Los Angeles, Calif.-based StreamCast released Morpheus 3.2 as a "spyware-free version" that seeks to thwart efforts by the Recording Industry Association of America (RIAA) to gather evidence against online music pirates.

The RIAA has already warned it would file thousands of lawsuits against individual computer users who share "substantial amounts" of copyrighted digital works.

In direct response to that threat, Morpheus will offer its users the option of connecting to its network via a public proxy server (define). A proxy server acts as an intermediary between two Internet users so that one user does not know the identity of the other. Morpheus won't be hosting the proxy servers but will instead direct users to a "worldwide network" of public proxies.

In addition, Morpheus 3.2 users will have to option to link directly to third party Websites that publish "blacklists" of IP addresses that snoop on file-sharing activity. "If a user chooses to click on any of these blacklisted IPs, those IP ranges will be blocked from the users computer," StreamCast Networks said in a statement.

"Morpheus 3.2 is our response to the legitimate concerns of our users about the invasion of their privacy. While we do not condone copyright infringement, we also do not condone the targeting of our users and the invasion of their privacy," StreamCast Networks chief executive Michael Weiss said.

The latest Morpheus client also adds bandwidth usage improvements, image and video file scanning to help with searches and new technology that can pinpoint low-quality or degraded files.

Morpheus is not alone in the battle to throw the RIAA's lawyers off their trail. Israel-based iMesh said it would plant "decoy computers from fake locations" within its network to trade non-existent files.

The iMesh file-spoofing move is a tweak of the RIAA tactic of releasing fake files on public networks to deter illegal piracy of copyrighted works.

Spain's Blubster has also rolled out a new version of its P2P client to block full access to the list of files its users share. Blubster 2.5's response to the RIAA includes a private protocol that features a "serverless" P2P network with anonymous access.