Here's my CSB addition... so I just moved and when I submitted my move notification to the US post office, they sent me a bunch of stuff including advertising for a service called USPS Informed Delivery.
Post 9.11, the post office has been scanning the front and back of all mail delivered in the US. This is the corollary physical post anti-terrorism measure to scooping up all text messages and email metadata. Somebody realized that these scans could turned into a service where you can see what's in your postbox without having to visit it. Helpful if you don't get to the mailbox frequently or are traveling.
I signed up for the service and they used some sort of knowledge based question to verify I actually lived at the new address. Questions like "Which of the 4 addresses did you live at previously?" The IRS has tried to lock down their systems with questions like this and failed miserably. With the amount of data accumulated about us all, if somebody wants to dig up info on you, it's possible through a myriad of data broker services.
I failed the knowledge based identity test, I was asked to bring my ID to a post office. I think either they didn't have the right profile information for me, or were confusing the profile information for a prior occupant of my new address. My driver's license has a badge from the DMV showing that I had registered the new address with the DMV. This badge was delivered by mail to the new address. I presented this ID to the post office.
After all this, my request to join the Informed Delivery program was rejected. I have notification submitted with the post office of my change of address, I presented valid DMV ID that was not accepted despite it having been correctly updated with the DMV. While I was there, I was asked to show a second form of ID which was not indicated as a requirement on the program documentation. I've escalated a request for explanation to the US post office without answer.
While I agree the US post office could provide identity verification, they are definitely not geared to actually do so.