I wouldn't be surprised if there is some truth to this. Although I know of fairly recent CD's, I also have heard of fairly recent cases where there was no CD but rather knock and talk interrogation from postal inspectors (for fairly small amounts) or field investigations leading to SWAT raids (for bigger amounts). Also heard of one case where they waited for the suspect to leave after the delivery, a full day later, and pulled him over on the road like a routine traffic stop.