Hawaii is NPC'd.
On another note, it isn't cheating. I didn't leave your browser open and there's no rule against looking at plans, copying them, and pasting them elsewhere.
Precedence: In IOT IB, neither Siam or I were kicked for copying and pasting UNA plans. Likewise, in IOTVI, I and the other people didn't get in trouble for posting Asian Union plans, despite the group being public (accidentally) in the first place. You have a brother you know you're playing against in a strategic IOT and I can't be held responsible for him taking your plan.
I don't discuss what goes on in either side's SGs. That is up to the players in that group. By leaving your browser open, your information became just as public as the Asian Union's plans were in IOTVI.
If you're going to get mad, get mad at yourself or your brother. Not me, the GM, who has no obligation to tell both sides what I hear in chat constantly or what I read in SGs.
Edit: In short, I can't be held responsible that plans were leaked when two players are playing in the same household. This is a Cold War-esque game where everything from unit movements, buildings, grand strategy and supply lines are incredibly important so I'm not surprised that leaks happened. However, given that I made up the ruleset so only one faction could win in the first place, I would assumed that anyway who post plans actively would have to be griefing their own team.
Edit2: If you guys really want to prevent this from happening again, I suggest the two of you come to some kind of agreement on going through each other's plans. Again, not my fault in the slightest.