I don't know about you - but I hold my privacy dear and guard it with vicious posessiveness . So it comes as a whack in the face when someone betrays it. And move this to a wider circle like your credit card, your medical history and you have the perfect recipe for identity theft or am I being paranoid here ?
I am in a car with an acquaintance who happens to be a customer service person at a bank. So she's making calls and doing the humdrum I-am-super-busy-have-to-talk-while-I-Drive thing ( oh ! Did I mention she was driving ? Yeah , my life flashed before my eyes. Food for thought and another post ! ). She reels off credit card after credit card numbers and names to someone at the other end . So I think OK, maybe she's giving it to someone at her office to verify. And then she says " This is all I can give now . When you show me the money, I can do more". I just witnessed some poor guys information handed out to some over-zealous sales organization. She might as well have given his other information while she was at it .
And then again , there are those who will easily share their passwords with colleagues, friends and relatives. I know at least one person who shares his ATM PIN with his friends and colleagues and everyone and their uncle knows what his password anywhere would be ( it's not rocket science , this guy jumbles his birthdate around ).
The former , a breach of trust and privacy and the latter also is the same but it's self inflicted.