People stealing your shit sucks. I had a drummer that left my band 2 years ago that did that. He started playing with another group and next thing you know they started playing (live) one of the songs that me and my bass player wrote before he was even in our group. I about whopped his ass afterwords.
The guy I know had all his songs stolen by the band he left, they got copyright and he could do nothing.
thats probably one of the most annoying things that could happen...i've wrote a few songs and i know the emotion that many writers put into them...and to have them half inched by someone who only wants to exploit them for personal gain...that gets right on my ****
you can use poor mans copieright. you take a cd of the music you made. put it in an envolpe and mail it to your self. but dont open it the postige date on the letter will hold up in court.
also i am a musicain i do vocals in a Thrash/Death metal band
called Nothing but Losers
you can check it out here