I imagine that would be easily spoofable (though that obviously takes a bit more preparation than lying about having an IUD), and almost certainly raises some p

I imagine that would be easily spoofable (though that obviously takes a bit more preparation than lying about having an IUD), and almost certainly raises some privacy concerns. Not to mention the social aspects. "Awww yeah baby, let's do this thing. Let me just... take out my RF scanner and verify that you have an IUD."