We have the equivalent scam in Canada that references the Canada Revenue Agency and RCMP.
One anonymous person recently duped wanted to tell her story and it was written up on of the local newspapers. Basically, she seemed to be a smart person and knew of the scam but she's irrationally scared of authority/getting into trouble. So, when they called her up with a ridiculous request to make payment for an incorrect tax filing, under threat of being arrested immediately, she did so. She obviously feels stupid now.
But the scammers are preying on people willing to blindly follow requests of an "authority" figure over the phone whether out of fear or ignorance. And there are numerous similar examples where a prank call successfully instructs a person to do pretty stupid things: strip searches, smashing all their windows, etc.
People have to be willing to question authority. That doesn't mean you have to be a jerk in how you go about it though. And the people fielding such questions need to have the patience to answer the questions, understanding that people can't expected to be sheep. Situation dependent of course.
