>>2898141This time around got me thinking it might be Tachibana trying to resurrect Lain. In the game Lain says she wants to leave her body and spread herself across the wired, and she's in contact with a Mr.Tachibana over the wired.
Maybe Lain did live on in the wired, and to try to stop Eiri Tachibana Labs tried to resurrect the genius Lain. It would sort of explain why some of Lain's personality traits exist only on the wired.
Though the game also suggests Lain had been closely monitored her whole life, so that points to it being a previous attempt I suppose.