...because you never had that right, pre or post-9/11.
Probably the most infuriating claim about the Boston Logan fake bomb incident is that somehow our rights are being taken away. That right hasn't existed in 88 years -- it's called Schenck v. United States, and was decided on March 3, 1919. This is the "Fire in a crowded theater" decision from the Supreme Court. It doesn't matter if a keen eye can tell you it was just a breadboard with LEDs and a 9v battery -- if you are doing something that creates a panic in a public place, you have no right to free speech. Random electronics and wires on your chest in an airport certainly qualifies.
But to those who believe rights have been lost, you should feel better because her rights are completely intact. Now she has the right to defend her actions in a court of law. If it is determined that her right to free speech was infringed upon, then I guess we'll have people with the right to wear fake bombs on their chest. She has the right to go on the Today show and cry to Matt Lauer about how it was "free speech." She has the right to sue TSA if she feels she was treated unfairly. Seeing as this is the United States, she can probably sue Duracell for making a battery that looks bomb-like.
Many other countries would not give her those rights. If it was Tel Aviv airport, or Moscow, or Jakarta, she would not have been given the right to live. They would have shot her in the face if they thought she had a bomb and was not responding to their questions about it.
So when commenters on Slashdot and other geek-asshole websites say things like "Arresting her is what they do in oppressive America. In my country, they would just leave her alone", remember what rights she still does have. No other country lets people test the boundaries and keep their rights like the United States.