I am so, so reassured that the "experts" will be patrolling the stands, on the lookout for "suspicious" attendees.

Can someone be arrested and detained just because these so-called experts just decided that the person seemed suspicious?  Or would they have to have found a weapon or another type of evidence?  

I hope that at some point in the near future, the government has to prove that this TSA program is effective because otherwise, it's the kind of thing that could easily become a very slippery slope.

How is that substantially different than "TSA Behavior Detection Officers, who are trained to observe characteristics indicating a person is about to engage in wrongdoing"?

Here's Schneier on behavioral profiling

as a control, here's Schneier on NY Subway searches.

And here he is interviewing Kip Hawley

The type who believes in blowing up the Super Bowl doesn't think he/she is doing anything wrong...they are fighting a just war against infidels in their warped minds, they are doing right in their warped minds. So how is a "behavior detection officer" gonna sense impending wrong-doing when the wrong-doer doesn't think he/she is doing anything wrong, in fact they think they're doing right?

The American Civil Liberties Union says that the technique is unproven and that its use at a stadium sets an alarming precedent for police inquiries.

"Police shouldn't be stopping and questioning people unless they have some credible reason to suspect them. Behavior detection is just too vague," ACLU analyst Barry Steinhardt said. He noted sarcastically, "If we're going to use this at high-profile sporting events, why not start using it on streets?"

Lets talk about the basis of this objection.  That it is unproven.  Before any of you advocate another concession of our civil liberties you might ask yourself these questions.  Whats the scientific basis for behavioral profiling?  How do we know that behavioral profiling is a valid technique?  

For example, one of the behaviors that they profile is direct eye contact.  In some cultures direct eye contact is thought of as an indication that someone is lying. Some people think it is a sign of disrepect.  In other cultures, it is a sign of disrespect to look someone in the eye.  So if the same behavior can have different interpretations how can you argue that profiling based on behavioral characteristics has any validity?

I remember my frustration years ago when I felt afraid in a public place and asked police to keep an eye on a certain individual who were (I thought) doing something mildly illegal and seemed threatening to me.  The police told me they could do nothing unless a "crime" was committed.  My frustration was that I asked them simply to keep an eye out, nothing else, and they basically refused to do even that.  I did not like waiting for someone to actually do me harm before I could obtain any kind of help.

And in theory a casual interview could clarify behavior that was indeed innocent but appeared threatening.