It depends on how it is structured. See US v. Davis as quoted above:

It seems pretty clear, as stated here elsewhere, that the 9th Circuit has disagreed with you, in Torbet (Torbet v. United States, 298 F. 3d 1087, 2002), Gilmore, and Davis. So long as the prospective passenger has the option of turning around and declining air travel rather than submitting to the screening process, the court has found that the security procedures have not been unconstitutional. (Important: the courts have acknowledged a constitutional right to travel, but NOT a right to travel by air per se.)
This was stated explicitly (Gilmore) with regard to the challenge on the basis of the Fourth Amendment:

And why wouldn't the court find the same for a Fifth Amendment challenge -- so long as the prospective passenger retains the option of remaining silent and turning around and leaving rather than agreeing to interrogation (or agreeing, perhaps, to secondary screening in lieu of the preliminary step of interrogation)?



It would seem that the strongest constitutional challenge to this new security procedure would be directed toward being asked to state personal private information (eg purpose of travel and with whom you are/were meeting*) in full hearing of others, on the basis of an expectation of privacy.(Katz v. United States, 389 U.S. 347, 361 [1967] [Harlan, J., concurring]). Is asking for that kind of personal, private information, particularly in public, reasonable and, crucially, is it "no more extensive nor intensive than necessary, in the light of current technology, to detect the presence of weapons or explosives"?(Davis)

*It seems very unlikely that an argument that being asked to state your name to the screener in the presence of strangers would be considered a violation of the Fourth Amendment, given that I suspect the courts would be unlikely to find that there is a reasonable expectation of keeping one's name private in the screening process. By presenting him- or herself to the checkpoint, and subsequently to the gate, a prospective passenger implicitly consents to having his name spoken in public, just as occurs in a doctor's waiting room, a school, or in many government offices.

There may indeed be an incremental expectation of privacy in not audibly stating your name at a public checkpoint. For example: you might be a celebrity traveling from DTW to DAL and not be recognizable, but you have a distinct name that would be easily recognized. Not pronouncing you name when it is clearly written on the boarding pass will avoid someone else standing in line from hearing that name and calling the Detroit Free Press, and from there finding out you live in a mansion.

This is over and above announcing to local thieves hanging about name, dates and destinations and durations of trips, making your house easy pickings. That's why my luggage addresses are business addresses. After all, not everyone hanging around a check point is as honest as the TSOs.

Huh? Who besides TSOs and prospective passengers, who are watched to ensure they move through the queues, is allowed to hang around a checkpoint?

Neither do I. That said, I agree with the below.

How many people have posted here that one cannot hijack a plane with a knife anymore? You can't blame the IAA for letting him onboard with something he couldn't hijack the plane with.

They profile (in every sense of the word) and then search with varying intensity. If they don't find anything that can be used to hijack the plane, or to blow it up, they let you on. They don't ground people for 'bad intent'.

Gilmore was presented with the opportunity to not show ID and be subjected to further screening of his person and property. Instead he chose to leave the premises and sue. Other cases revolve around the screening of persons and property for WEI, not for playing 20 questions. The standard out of Davis is �[an administrative search is allowed if] no more intrusive or intensive than necessary, in light of current technology, to detect weapons or explosives, confined in good faith to that purpose, and passengers may avoid the search by electing not to fly.�

One has to use some tortured reasoning to reach the conclusion that questioning is for the purpose "to detect weapons or explosives, confined in good faith to that purpose". As such, I think that a passenger would have a strong case if he was denied access to the sterile area solely for refusing to play 20 questions.

Gilmore (from post 323 above):
The Court (on the basis of Davis) has already accepted behavioral profiling as a (potentially) lawful form of administrative search. TSA just needs to make a convincing argument that playing 20 questions is a key part of behavioral profiling.

And if TSA can convince the courts that the details of the answers provided to 20 questions aren't in themselves of material interest and that the agents asking the questions are only interested in how the prospective passenger behaves during the interrogation, well, that's icing on the cake.

I don't know whether this line of argument would fly in the lower courts, but my sense is that the Supreme Court as currently configured wouldn't have a problem accepting the argument from TSA.

Admittedly, if the 20 questions being asked were more innocuous than what we've heard so far and didn't encroach on personal private information (eg, "how was your trip to the airport?" as opposed to "with whom will you be meeting on your trip?"), it would be easier to avoid the charge that the interrogation is "more intrusive or intensive than is necessary."

The other questions though, again, is how does playing 20 questions benefit the passenger?

As far as I've heard, regardless of the performance during 20 questions, all passengers are still required to complete body scanning or magnetometer screening as well as to have their carryons scanned and possibly hand searched and/or swabbed for explosives toxicology; and if there is any question about the results of their body scanning or magnetometer screening, they are still subject to wanding and/or patdown.

So what is to be gained by 20 questions as currently proposed?

Is there a shred of evidence that the 20 questions procedure raises the sensitivity of detecting weapons or explosives compared to body scanning etc alone -- in trying to identify individuals who might have weapons concealed in body cavities that cannot be identified by the other routine screening techniques, for instance?

It only begins to make some kind of sense if a favorable behavioral profile generated during the interrogation would allow the prospective passenger to be selected out of one or more of the other screening steps, or if there is evidence that using the behavioral profiling with the interrogation in combination with the other screening measures increases the overall screening sensitivity.

thanks to the collective cowardice of the Federal bench, I agree that having one's name publicly spoken would likely pass Constitutional muster. But the follow on questions? At some point, there must be at least once Federal judge with balls that is willing to call a halt to the madness.

I'm not arguing about them profiling (they do) but I fly in/out of TLV numerous times a year, and many times, I'm with other, quite clearly Arabs. Many (most really) of them do not go through a much more stringent security than I do. They got more questioning, but this is questioning while they're anyways on line, waiting to check bags. The actual hand bag check is the exact same for them and for me.

The only blame I'm attaching is to Bloomberg and anyone else who:
a) advocates Israeli-style security for the US
b) uses inaccurate statements while doing so.

In fact I doubt anyone could hijack (as in take command of) any flight any longer, although explosives are an ongoing risk. Which is why I disagree with profiling, BDO voodoo, 20 questions or anything else which distracts from (and adds nothing to) the primary purpose of security - keeping dangerous materials off airplanes.
Expansion of empire and aggrandizement of staff. If you mean security-wise though, nothing, absolutely nothing y'all.