“Can’t we just drone this guy?” Clinton openly inquired, offering a simple remedy to silence Assange and smother Wikileaks via a planned military drone strike, according to State Department sources.
The claim has never been independently made outside of True Pundit, and it cited anonymous State Department sources.
Clinton claims not remembering saying that.
I don't recall any joke. It would have been a joke if it had been said, but I don't recall that.
It very unlikely that killing Assange with a drone was a serious suggestion, as he was residing in non-hostile countries and embassies that that were unwilling to extradite; they would probably be very upset by a drone kill. Other more conventional methods of killing or capturing seem more plausible.
It could have been said as a rhetorical question for taking decisive (possible lethal) action. There's really no verifiable way to know. "Extraordinary claims require extraordinary evidence."