The OP doesn't link to the decision in question, in which airport screening per se was only an ancillary issue in the course of deciding whether the TSA could reach into the guy's pocket after he dropped his pants - and yes, he dropped his pants.
The full decision is here, but take a look at what was cited along the way:
http://www.ca3.uscourts.gov/opinarch/043841p.pdfFirst, there can be no doubt that preventing terrorist attacks on
airplanes is of paramount importance. See United States v.
Marquez, 410 F.3d 612, 618 (9th Cir. 2005) (“It is hard to
overestimate the need to search air travelers for weapons and
explosives before they are allowed to board the aircraft. As
illustrated over the last three decades, the potential damage and
destruction from air terrorism is horrifically enormous.”); United
States v. Yang, 286 F.3d 940, 944 n.1 (7th Cir. 2002) (“the events
of September 11, 2001, only emphasize the heightened need to
conduct searches at this nation’s international airports”); Singleton
v. Comm’r of Internal Revenue, 606 F.2d 50, 52 (3d Cir. 1979)
(“The government unquestionably has the most compelling
reasons<—>the safety of hundreds of lives and millions of dollars
worth of private property<—>for subjecting airline passengers to a
search for weapons or explosives that could be used to hijack an
airplane.”).
...
Sitz makes clear that
“his passage from Brown was not
meant to transfer from politically accountable officials to the courts
the decision as to which among reasonable alternative law
enforcement techniques should be employed to deal with a serious
public danger.” Sitz, 496 U.S. at 453. The “effectiveness” prong
search, there is no effective means of detecting which airline
passengers are reasonably likely to hijack an airplane.” Singleton,
606 F.2d at 52. See also Marquez, 410 F.3d at 616 (“Little can be
done to balk the malefactor after weapons or explosives are
successfully smuggled aboard, and as yet there is no foolproof
method of confining the search to the few who are potential
hijackers.” (internal quotation marks, brackets, and citation
omitted)); United States v. Skipwith, 482 F.2d 1272, 1275 (5th Cir.
1973) (procedures requiring the screening of all passengers and
luggage “have every indicia of being the most efficacious that
could be used”). Additionally, it is apparent that airport
checkpoints have been effective.
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I highlighted one point in particular that bears some thought as to how a court is going to handle a battle between plaintiff's experts and the presumption of administrative competence which is going to adhere in the TSA's determination of policy.