Unless it's been clearly and definitively stated that it's someone with regular posts in previous books -- someone in, say, the first 20 pages of Fastjack's
Shadowland/Jackpoint Posters pdf -- then I think most bets are going to be off. It could easily be an unrevealed character in the game world, someone who knows a lot about a lot of things but who has only posted very rarely until recently. Consider the knowledge base:
- CAS vehicle use
- Aztlan politics
- Cartel info and sources (i.e. crime)
- Media pirates
- Denver politics
- Great Dragons (very much so) and their minions
I have a minor doubt about it being a techie, though it's still possible; note the comment about an optic system having a magnetic field. This is someone who has a very wide range of interests and an information pipeline with many intakes. If he, she, or it posted in pre-4th Shadowland, then it was probably across a lot of books, though most of the information above lies primarily on the social range.
Me, I'd look for posters who spoke primarily in the sourcebooks on Aztlan, Denver, and Dragons of the Sixth World. Maybe Shadowbeat, too ...
Or maybe it's being held for a character of a new writer, so that their 'old codger' poster can come out of the woodwork.
