We've received a few news tips and heard a few rumors as to why the game was taken offline, so we decided to contact Funcom directly for the full scoop. Director of communications Erling Ellingsen gave us the low-down:
What's happened is that the activity levels on sharing to Facebook has been significantly higher than expected, and we have been asked by Facebook to make certain adjustments. So we are taking down the experience now and will be bringing it up again once the necessary adjustments have been made.And there you have it. We'll update the story as Funcom brings The Secret War back online or if there are any further developments.
Even shortly after launch yesterday we had tens of thousands of people playing and sharing actively, so the interest for the experience has been very high.
[Thanks to Adam for the tip!]