This is all fascinating to a linguist. I don't know how seriously to take these claims. I certainly believe that the people making the claims are telling me what they believe to be the truth, and that they are presenting accounts of their reality as they perceive and construct it. No question in my mind about that. [I understand that someone might make up a message along those lines just to see whether I would believe it and how far down a garden path I could be led, especially in the context of a discussion of cyberbullying; but that's not the impression I'm getting. If that's what's happening, it's being done extremely well. So far as I can tell, all these accounts are sincere and truthful (whether they are true or not), rather than being a form of fancy and highly-skilled cyberlanguage attacks on a Target Linguist.] The reason I don't know how seriously to take the claims is that human beings are notorious for the weakness of their intuitions about what goes on in their own heads. Their Head Nannies tell them stories, and they believe them. Because, after all -- your Head Nanny is in your head, which ought to make her a reliable source, right?
Nobody -- yet -- has sent me a message claiming that in ordinary non-narrative conversation what they do is hold in their head a vast decision tree with all the possible utterances that might be useful in that conversation, so that the option of hypertexting is always available to them. Like a champion chess master.
And what all this brings most immediately to my mind is an example of its opposite -- the Navajo style of oral storytelling described to me by my own Navajo consultants in the 1970s. If I were to do it in English [in a condensed version, for the sake of your space and time] it would sound something like this...
The Boy Who Cried Wolf
Once, they say, there was a little boy who spent his days looking after a flock of sheep, and after a while he found that truly boring. So one day, he having become so bored that he just couldn't stand it any longer, he started shouting "Help! Help! There's a wolf attacking the sheep! Help!" The boy having shouted that a wolf was attacking the sheep, and the people having heard him, they all came running to help him drive the wolf away -- but there wasn't any wolf, and so they went away again. The boy having found that this trick made his days less boring, he tried it again; once again he shouted that a wolf was attacking the sheep, and once again people came running, and once again -- there being no wolf -- they went away again. The boy having done that several times, and the people having always come running, and no wolf ever having been there any of those times, a day came when there really was a wolf, and the boy shouted for help again, and it wasn't a trick. "Help! Help! There's a wolf attacking the sheep! Help!" he shouted, over and over. But the people having come running so many times and never having found a wolf yet, they no longer believed him, and nobody came. And nobody having come to help him, the boy was all alone and so, they say, the wolf had no trouble killing a sheep and carrying it away.
Disclaimers: I have absolutely no information about whether this style was used in ordinary narrative conversation in the 70s -- like when people came home from a hard day at work and were telling their families about that day. I don't know whether, when a Navajo child asked a grandparent for a story about his or her childhood, that style was used. I don't know whether it's still used today or has been abandoned. I'd have to ask my consultants, and I no longer have easy access to them. [Maybe someone among you here on LiveJournal knows these things, in which case I'd welcome the information.] I do know that in my opinion doing this in the Navajo language is easier than doing it in the English language; Navajo has recapitulating devices that seem to this native speaker of English to be less cumbersome than the ones available in English.