The whole verification of somebody over a phone without a previously agreed non-personal identification code has always bemused me.
The difference between "Hello MR X this is your bank, before we talk any further we need to ask you a few security questions about you" and "Hello, what you wearing" are not that far apart.
I recall one long conversation with my mobile telco provider at the time becasue they called from a number I did not recognise and ended up in a you move first in the quest to verify each other. I asked ok so you want my date of birth, tell me the year and I will confirm the rest - you see the stalemate that ensured. For them to prove they were who they said they would of had to devuldge private information they can only devuldge to me after they have proven that I am me, yet you see the lament of it all.
The focus is all about individuals having the abiulity to prove who they are to people who do not prove who they are and then cause both stress with fraud and the like wondering how can this happen.
Sure you can use a different email address for every secure contact and even phone numbers and address's to some level of protection. But you only get one date of birth, one mothers maiden name, one my first pets name and with that I like to vary the pet and maiden names in that I never devuldge the true actual answears. Nothing at all saying your mothers maiden name is "Joan of arc" or other random answears that you will remember.
I do advicate getting a preium number or a number that pays you be it some mobile service that gives you minutes for every minute people call you or some payback premium number. Then let that spam out and enjoy all the cold calling and sales calls you like knowing you gain from it.
But when you get a call from somebody who has to ask you security questions then ask yourself, how do they prove who they are to you before you give them private confidentual information.