Really!!!???

Was the market in Russia really weak and refused to go for SPX because, that someone knew about the impending terrorist attack! And after the news, that nothing big happened decided to buy the market!?
Sell rumours buy news!
I would like to know if this thought has real confirmation.. Maybe the relevant services knew about it, but did nothing( I mean warned). Then a situation arises similar to 9/11, when they accused Bush why they knew about the rumors and did not warn anyone. And now the situation is similar in Moscow..