I blame the banks.

I blame the banks.

In the US, banks always remind us that they will never ask us for a password on the phone. However, they must ask for some kind of weak authentication because they don't know who answers the phone and people are so paranoid about privacy now, they would not tolerate a bank telling another member of the household about their bounced checks. That weak authentication could be a birth date or something. I presume that when the recipient isn't willing to let that information out, they offer the alternative of the recipient looking up the bank's customer service number and calling back.

Many of us are not scared enough to bother; we just give them the information. The actual risk to you from someone knowing your birth date or bank account number is much less than the media hype indicates.