Music lovers are fighting back against new efforts by the recording industry to keep people from swapping tunes online for free.

The people who make file-sharing software are offering upgrades designed to keep the recording industry from finding out who's doing the downloading.

StreamCast Networks says the upgrade for its popular Morpheus file-sharing software has been downloaded more than 300,000 times since its release last week.

The company's Web site says the new privacy features include using proxy servers.

The Recording Industry Association of America has announced plans to sue individual swappers. It's building cases and has already issued hundreds of subpoenas.

A recording industry lawyer remains confident, despite the software changes. He said nothing invented will completely cover the tracks of a tune thief.