In RES's I get scanned quite frequently and told by would be pirates "how do you guys make a living" and "what a waste" when their scanners reveal that my Vulture didn't have any cargo on board. No cargo on a vulture? You needed scanners to help you work that out?
For the most part the rats then just fly off in search of another target. Either that or, because I'm not on friendly terms with the local pirate faction, they go hostile before scanning me because I'm a recognised threat.
At present I only get interdicted by the local pirate faction and they immediately attack when I submit to the attack, because they're after a hostile rather than my cargo. This at least makes sense. It doesn't change the end result mind you and my only complaint is that they don't interdict me more often. KaChing!