Essentially what they are saying is that at American airports if the government finds someone's behavior "suspicious" they have a right to detain them and search them for evidence of terrorism. If they don't find evidence of terrorism, but they still find the person "suspicious" they can then call in police, who will look for evidence of non-terrorist related crimes. What constitutes suspicious behavior? Only the "specialist" knows for sure. And if you demand to know why they are calling the police, that constitutes "escalating behavior" which gives them cause for further inquiry.
This is how the creeping police state slowly takes over. They use the excuse of national security to chip away at the constitutional constraints that prevent the government from abusing its authority. The citizens are in a constant state of paranoia, worried that what they know is innocent will "look" guilty and afraid of asserting their rights because the act of asserting them is considered evidence of something to hide. There are thousands and thousands of people in every aspect of American life now granted the authority to do this in the name of anti-terrorism. [my ems]
"Yessir, he just looked guilty."
And it's getting worse.
It makes it easy for them to control the masses but what they forget is that one day, the masses will have had enough.