<p>When the recording industry said Wednesday it would sue heavy music sharers, it left one unnerving question unanswered: Just who would they consider a heavy sharer?</p>
<p>In a conference call with reporters, the Recording Industry Association of America's President Cary Sherman said the group will begin collecting evidence against those who offer "substantial" amounts of music online to others over peer-to-peer networks, then will file hundreds of copyright-infringement lawsuits beginning in August. But he declined to say specifically what "substantial" means.</p>