The search warrant application and supporting affidavit for the DJ Drama/Cannon/Aphiliates raid is posted over at freethedjs.com. (Thanks FvL for pointing this out in comments.)
These documents make clear that the police are alleging a violation of Georgia Code 16-8-60 (as the underlying predicate for the state RICO charge). The documents supporting the warrant application claim the sales of mixtape CDs constituted a "true names" violation, and also seem to suggest these sales violated the other part of GC 16-8-60 as well (subsection (a)) which criminalizes distribution of CDs without permission of whoever owns the "master" copy. As discussed previously, the "true names" part of the statute was upheld by the Georgia Supreme Court just a few months ago (although on a different set of facts), while the "unauthorized distribution" provision seems to run counter to federal copyright law, which preempts state laws that attempt to regulate in the area of copyright. The affidavit also seems to suggest that Georgia police may be misreading what the Georgia "true names" law actually requires, but that's a topic for another post.