We've actually planned and developed some pieces of software to allow this, however the main issue is that unless a very big amount of people use it, it's not going to work. Even if I and my friend 1km away uses it, unless there are enough users between us that can relay our messages, it's not going to work.

So we gave up, knowing that 51% would see it as an act of terror or smth, and even if they didn't, they wouldn't use such software or hardware.