Alright then.
New Ruling: Players may now send their turns via PM. Actions will still be revealed at the end of the turn.
Caveat: Troop movements that pass through rival player territories will be notified to that player. This does not count if the troop movement ends in a rival territories; e.g. attacking from a neutral territory to a rival territory, or passing through one neutral territory and then attacking a rival territory.
Spy networks or Scout units resident in a territory will also detect troops that pass through it, regardless of whose territory it is. This includes the territory the troop movement starts from.
Worked Example: If Gnomish infantry moves from Central Farland to North Bleater to South Bleater, Arcadia will not know about the movement of the troops because they do not reach Arcadian territory (S Bleater) until the end of the movement.
If Foul has a Spy network in Central Farland, he will know about the movement because the infantry move out of C Farland as part of their movement. Foul's spy would report that a Gnomish army left C Farland and moved into N Bleater. If Grouting has a Spy network in North Bleater he will also know about the movement. Grouting's spy would report that a Gnomish army entered N Bleater from C Farland, then left to attack S Bleater. Either party could alert Arcadia to their coming doom if they wished.
On the other hand, if Grouting's spy network in North Bleater has been compromised by a Gnomish Disinformation Feed, Farland could disguise the passage of those troops completely, or else give false information. So Grouting would be unaware of the troop movement because their spy has been compromised, Foul would know accurately that the army has moved from Central Farland to North Bleater (but would not know where it headed from there) and Arcadia would remain completely unaware unless they were alerted.
Scouts: Or, if Arcadia had a Scout unit present in North Bleater it would report the arrival of the Farlander army in North Bleater from Central Farland. Unless the Scout was killed (a free action for any military unit) it would then report the movement of the army to South Bleater as well.
Edit: Scout units have been added to the OP as a normal unit that anyone can build without needing any techs. Scouts can be killed as a free action by military units, but only have an upkeep cost of £5 and a hiring cost of £80. Cheap and disposable, in essence.