Verifying Bank Security
My approach to this was to give the bank/credit care companies a password that they must use when they call me. I always refuse to provide any information until I have positive confirmation that the caller is who they say they are (using the password).
At first the banks simply didn't understand the concern and would often ask me for that password until I explained (again) that the password was to confirm THEIR identity. This approach has worked very well for me.
Biting the hand that feeds IT
