Various financial institutions, government agencies, etc., use public records information to confirm people's identities, as touched upon in UPS my choice -- How can I access my public records? The information often includes relatives, past addresses, banks that have serviced your loans, cars you've owned, etc.
By definition, if the information is obtained from publicly-available records, anyone should be able to look up this information. I understand that it prevents random strangers from casually guessing my information and cracking my account, but I see ads all the time for $40 instant public records background checks.
If someone wants to break into my financial accounts or download my tax returns and steal my identity, what's to stop them from just searching public records themselves or buying a report? Maybe decades ago it was more difficult to search public records because you had to physically travel around and/or make a lot of phone calls. But in an age when almost everything is instantly searchable, how and why are public records considered "secure enough" to confirm anyone's identity?