Streaming mp3 via xml hacked(being downloaded)

I made this site for a dj/producer, and unfortunately I found out that someone has hacked my swf, found the xml file on my server which revealed the location of the mp3 that I am streaming, and shared that link information via music message board. Which I guess is a good thing in a way as far as advertising (grass roots promotion, passing his mp3 around on P2P systems), but my client is concerned that dj’s might be playing his mix and getting paid for his hard work and time he put into this intricate hour long mash up promo (60 tracks or something in one hour).

Anyhow… does anyone know of a way I can prevent people from downloading this?

It’s bad for me as well because the mp3 is rather large (75 mb) and having lots of people leech my bandwidth I use to host other sites is frustrating.