Companies themselves don't do much to help reinforce defences against this type of scam, though. For example, Sky and BT (to name just two) are bad for this. They cold-call you (the customer) along the lines of:
BT: Good evening can I speak to (the account holder) please?
Me: Speaking.
BT: We're just giving you a quick courtesy (read: sales) call. We noticed your calls are router via another provider (Sky Talk) at the moment, and wondered if you've seen the new rates BT are offering blah blah blah?
Me: Sure. Can you please confirm the full address and postcode related to my account? And now my account number, the amount of my last monthly direct debit to you, my date of birth and the third and sixth letters of my password, please?
BT: Um, we don't have access to that information.
Me: So how do I know you're calling from BT? You're wanting me to hand over payment information here.
BT: How do you know we're from BT? Well, I told you when you answered the phone.
