[dobbsbob]

There is plenty of extortion attempts, not for narcotics but for weapons sales many of those listings are criminals who will threaten you once they get an address according to their market forums. Buying a gun online isn't really necessary, here gangsters pop down to Arizona and buy any gun they want on craigslist or local classifieds for cash in a parking lot, then mail the gun(s) in pieces camoflauged with spare bicycle parts back to themselves.

Most buyers on these sites are using some kind of drop, like a virtual office that accepts the package then forwards it or they go pick it up.