A piece of Facebook usage that has long puzzled me, clearly illustrated in “Wilson Gray via PoliticusUSA” yesterday: a posting by Wilson Gray that linked directly to a PoliticusUSA story (on Romney and the economy). I would have labeled this “Wilson Gray from PoliticusUSA”, since the standard use of via ’by way of’ would have “Wilson Gray via PoliticusUSA” implying that the story started with Wilson Gray and came to us with PoliticusUSA as an intermediary: Wilson Gray in the SOURCE role and PolicusUSA in the INTERMEDIARY role. So the Facebook usage of via seems to have the participant roles reversed: PoliticusUSA in the SOURCE role and Wilson Gray in the INTERMEDIATE role.
(Similarly for other X via Y Facebook headers.)
From the OED (entry not yet fully updated; first published 1917 — but more recent dictionaries agree):
1. By way of; by the route which passes through or over (a specified place).
1779 J. Lovell Let. to Adams 13 June in J. Adams Wks. (1854) IX. 483 This night is the fourteenth since we first had the news of his victory, via New Providence. [first cite; intermediate place]
1931 R. Fry Let. 3 Mar. (1972) II. 654, I was ever so glad to hear, via Helen, of you. [intermediate person]
1981 G. Household Summon Bright Water iii. 149 He led me to talk of my interest in ancient economies and thus, via agriculture in the Forest of Dean, eased the way to my impressions of Broom Lodge. [intermediate topic]
(sense 2 is ‘by means of”).
The Facebook usage has the virtue of putting the discourse-salient participant — your Facebook friend (Wilson Gray in the example above; I have plenty of other examples) — first. That would explain the ordering of participants. But then the preposition via (rather than from) seems to come from the construction with the opposite ordering (iconically reproducing the path from SOURCE to INTERMEDIARY to you). So the apparent reversal represents a combination of two different constructions, one contributing the ordering (more salient before less salient), the other the preposition (via). Compare the discussion of “reversed blame” and “reversed substitute” in this posting.
Probably there is some discussion of this use of via somewhere, but I haven’t come across it.