Sadly, it breaks down. You ask someone if they are who they are, and that's about all you can do. Someone can lie. Has it ever happened? Probably, but I've never heard of it, and my legal department is pretty good about keeping up on these things. But the way the law is written, asking the question absolves the caller of legal liability.
It's not IT-grade authentication, but for wetware it works.
It's not IT-grade authentication, but for wetware it works.