A once-common sound might be returning to offices courtesy of the concern about privacy following the Prism revelation. Are you ready for the click-clack of typewriter keys?
News sources are reporting that the Russian Federal Guard Service is turning to typewriters in order to thwart electronic spying. It's an interesting approach to the problem, and one that's led me to wonder what other solutions are waiting to be reintroduced in our modern age.
As far as I know, carrier pigeons don't use readily hackable transport mechanisms. While it's certainly possible to interrupt a transmission through a number of means (from 10- through 28-gauge), the conversing parties tend to know that something has happened to the message. Given encrypted thumb drives or even solid cryptography of typed messages, the contents of the message themselves can be considered secure. What's gained in security might be lost in speed, though, especially in bad weather. Given sufficient time, however, most messages will go through.
Carrier Pigeon in WW I
Carrier pigeon messages generally made it through -- eventually.
Martin Lomasney, a Boston political rainmaker of the 19th century, might be the source of the most important advice for those concerned about privacy. "Never write if you can speak; never speak if you can nod; never nod if you can wink." It was intended to be advice to long-winded politicians, but people concerned with privacy have been heeding his words for the last century. It's possible that the NSA has come up with a consistent way of storing the metadata of winks, but so far no whistle-blower (or head-nodder) has come forward to tell us about it.
Martin Lomasney never nodded when he could wink.
Fringe is a common fashion trim, but it can also be used as a serious means of encrypted communications. The Inca developed quipu, a formal system of knots used as a counting mechanism, to keep track of trade goods and other items. It's not hard to imagine 256-thread quipu as a means of transmitting private keys for encrypting and decrypting messages sent by, say, carrier pigeon. Tie the knots into the fleece of alpaca, tie an encrypted message to the leg of a carrier pigeon, and send each on its separate way, and you have a seriously secure message transmission mechanism. At least, I think you do. I might have to explore the concept of the "homing alpaca" a bit more thoroughly...
Quipu -- knot your everyday encryption.
The point is, reverting to typewriters is just the beginning. If your enterprise is concerned with privacy, there are many technologies you can use to secure your communications. It just takes a bit of paranoia -- and a look backward through time. And maybe, just maybe, an intern to feed the alpaca.