I really don't understand how controlled deliveries work. What does it legally prove? I accept (and sign for) packages frequently and I don't always know what they are. Sometimes they are things I bought a long time ago, like electronics from China, and I sometime sign for people in my family.
So what does signing for something actually prove? If me signing for a package actually implicates me, it seems like an enemy could just mail something illegal to me with signature required and I would be screwed.
Am I missing something here?
CD is an easy way for LE to catch you red handed expecting a contraband delivery. That is federal jail time. Turning it down doesn't mean that you won't get arrested but it does mean that you have plausible deniability and a better chance of getting off the hook as long as you keep your mouth shut.