In Going Postal, Pratchett describes a technology which really existed but is now largely forgotten because the Morse electric telegraph was so superior. But many of the techniques used on the Internet - including encryption - were pioneered by the optical telegraph. The messages were also binary encoded, because a square on the telegraph hoist could be light or dark.
This is therefore doubly fitting, not only to remember Pratchett but to honour an early form of digital communication.
[edit - binary transmission was possibly first suggested by Francis Bacon, who had the idea of using two cannon with different characteristic sounds to send 1s and zeroes. It would have been a very expensive form of communication but would allow the government to broadcast a prearranged message very quickly, since in those days cannon shot could have been heard for miles.]
