In the article, the organizer is quoted:
The 4th Amendment explicitly states that we have a right to be free from searches and seizures. I see the backscatter machines, the pat downs, the 3 oz. restrictions on fluids, as completely egregious and in conflict with Constitutional rights ... to be free from having to submit to any searches and seizures to participate in commerce with any other party.
A couple of things wrong here:
First, the Fourth Amendment protects against unreasonable searches and seizures, not any search and seizure.
Second, the Fourth Amendment applies to government actions regardless of whether the subject of the search is engaged in commerce or not. Different concepts. And the Commerce Clause deals with the relationship between national and state interests, not the protection of individual rights, anyway.
The point is: this is an issue for a vigorous policy level debate about the level and type of security that is appropriate for airports. Unless and until the TSA changes procedures, the Fourth Amendment is not implicated, and trying to apply it just adds to the confusion.
The debate about airport security is interesting and vital. It will be most effective if it sticks to policy, not con law.