"No, Molly," Kingsley said gently.  "When you’re talking to someone you know who’s been Imperiused, there’s a change in them.  A sort of bliss on their face, a look that can’t be mistaken as anything other than intense pleasure.  Oh, she had a look of pleasure when Malfoy touched her, alright, don’t say it, Ron," Kingsley said when Ron opened his mouth to speak.  "This is different.  But I gather you know that, since you used one at Gringotts."