We’re familiar with the concept of ‘security through obscurity’, meaning if you make something difficult to find it becomes less likely to ever be seen (like a needle in a haystack).
But there are additional forms of security that paper mail offers over telephone and email (and all other digital forms).
These include, ‘security through inconvenience’ and ‘security through bureaucracy’.
The first is achieved by making the content as cumbersome as possible to discover. Think of a spook whose job it is to sift through all of your email messages, suddenly presented with a stack of paper correspondance. Even if the paper mail is written on postcards – open to the world to see – the mail could take an afternoon to sort through, while a lifetime of email can be scanned in a second.
The second is achieved by relying on the fact that most of our legal protections were established during an era when paper was the only form of recorded documentation. Warrants are needed to open mail, thanks to laws written long ago. This is apparently not true for email.
So, if you want to send a note to someone with a high likelihood that no one but the recipient reads it, write a letter, buy a stamp, and use your local post office.