That you are even asking that question answers it, IMO. We need to work harder at educating the public and those in our government. Free speech is one thing, subversion and out right treason are another.
There were pro-terrorist rallies in a number of cities on or about that day. You really have to dig to find coverage of them. Mostly it is in cyberspace, but still difficult to find.
That's why I really like the suggestion higher up in the thread for FNC to start a full show called "The Grapevine" and stock it with blogger-produced analysis, such as zombie's.