Icecast should run as user icecast2. But if he should listen on port 80, you run into trouble, cs nonprivileged users can't use privileged ports (lower 1024). You can do the following trick: Modify the /etc/default/icecast2 file, chenge the user to root. Then it will start as root, open the port 80, and then switch to the -user (icecast2) defined in icecast.xml. Ans voila, all is fine.