Unlikely, but still possible. That is part of the nature of random outcomes. I mean, CN is over 2 years old, and there's over 30,000 nations in play. That gives this sort of thing a decent chance of happening at some point.
A potential exploit with the 'multiple improvements purchase' feature would have let people buy a bunch of Border Walls at once without the citizen count penalty blocking the purchase of the last 1 or 2.
Yeah, KISS principle.
But maybe they do. I mean your country also has to fit commercial, industrial, military, transport and trade on the same land mass.
If possible, check the IP address of your new connection with that of the other person. There's a slim possibility of them being the same. I got a new connection a few months ago, at which point, a different online game I happen to play began telling me that I have the same IP address as another player.
http://forums.cybernations.net/index.php?showtopic=27840
Someone seems to have decommed a carrier and not lost their extra planes, so I'd say it works like Construction.
By any chance, were you looking at the "Avg. Individual Income Taxes Paid Per Day" for that?
Because the wonder affects the "Avg. Gross Income Per Individual Per Day".
The half-income effect lasts until the END of the day on which you can change out of Anarchy. I suppose it represents the riots and unrest taking that long to stop even though your Government has been reinstated.