This article is a couple years old but it gives an in-depth look at 1 individual who was distributing mass amounts of prescription opioids and tranquilizers in the Bay Area.
http://www.sfweekly.com/sanfrancisc...file-of-a-prolific-dealer/Content?oid=2183786
http://www.sfweekly.com/sanfrancisc...file-of-a-prolific-dealer/Content?oid=2183786