Lots of sentiment today that the USPS is way out of its zone of expertise in doing this -- and that is possible. But it's worth noting that the USPS has had its own legion of postal inspectors going back to the 19th century, when they were a (comparatively) huge part of the U.S. government, and the FBI, etc. did not exist. Some 1,200 postal inspectors are still around, and they play important roles on federal prosecu…
Sure, but the 19th century ended over 120 years ago. So that's kind of not relevant to how they're structured and operate today?
https://pasttenseblog.wordpress.com/2019/09/03/today-in-lond...
> The Post office was of central importance to this surveillance. The ‘Secret Office’ – an arm of what was basically a secret service, dedicated to opening post to discover plots against the government – was formed around 1653 under Cromwell’s post-Civil War republican Protectorate; but it proved so handy, the Office was continued after the restoration of the monarchy.
[...]
> Morland also recorded what he saw as the basic function of his devices and of surveillance in general: “a skilful prince ought to make a watch tower of his general post office… and there place such careful sentinels as that, by their care and diligence, he may have a constant view of all that passes.”
Samuel Morland was interesting and has some early computing devices.
https://history-computer.com/samuel-morland/
https://history-computer.com/samuel-morland-biography-histor...
https://www.headstuff.org/culture/history/terrible-people-fr...
One of the links talks about letters sealed in the Spanish manner.
https://regencyredingote.wordpress.com/2012/11/16/sealing-wa...
> It was then that the superior qualities of the new "Spanish" wax came to be highly valued. The basic formula of this new sealing compound was a blend of shellac, mastic, turpentine, chalk or gypsum, and a coloring agent, to which essential oils and/or fragrant balsams might be added to facilitate melting and impart a pleasant fragrance. This "sealing wax" could be melted to a thick viscous fluid which would readily and firmly adhere to the parchment or paper on which it was placed. While warm, it would take a clear impression of any seal that was pressed in to it. It would remain solid, even in the heat of summer, and was flexible enough to remain intact while affixed to the document on which it had been placed. However, it was extremely difficult to remove a seal made of this material and replace it after the contents of the sealed document had been read. This compound was more brittle than beeswax so it could be easily broken, thus providing clear evidence of tampering. Even if the seal could be removed unbroken, any attempt to re-affix a seal was nearly impossible, since, with such a low melting point, the image which had been impressed into it would loose its crispness, if not melt completely, if additional hot wax was used to re-attach it, yet another sign of tampering.