Is it reassuring that Secretary Chertoff is notifying the public to this threat ahead of time? It sounds to me more like a case of CYA, so when it happens no one can say, "Don't say we didn't warn ya!"
Would such an event provoke repercussions? Hot-heads will be hot-heads, mimetic doubling rivalry will be mimetic doubling rivalry, Hatfields and Ahmeds will be Hatfield and Ahmeds. There would (will?) be mourning, grief, grievance, and deep resentment born on the wings of such death and destruction. Yes, there would be repercussions.
It is in my mind that the bell-shaped curve would hold. A few nut-cases would do their best to "share the grief" with indiscriminate victims of their own making. A few on the other end would roll-over and play dead in pacifist idiocy. The vast bubble in the middle would react by the kind of vigilence I saw during our "Beltway Sniper" days.
Let us prepare our hearts for chivalry, legitimate defense, and the kind of charity Our Lord speaks about in yesterday's Gospel: [Lk 12, 4-7]
I tell you, my friends,
do not be afraid of those who kill the body
but after that can do no more.
I shall show you whom to fear.
Be afraid of the one who after killing
has the power to cast into Gehenna;
yes, I tell you, be afraid of that one.
Are not five sparrows sold for two small coins?
Yet not one of them has escaped the notice of God.
Even the hairs of your head have all been counted.
Do not be afraid.
You are worth more than many sparrows.”