HOWEVER, this changes drastically when the guards are replaced by federal agents, at which point the voluntary business nature of searches is replaced by a plain Constitutional violation: NOTHING in the Constitution provides for such searches by federal agents (even when motivated by your vague fear of terrorists with nail files); to the contrary, the 4th Amendment plainly restricts such warrantless (in both senses of the word) searches.
Compare recent comparable decisions on the 1st and 2nd Amendments:
Re: limitations on 1st Amendment
Prior restraints on pure speech are highly disfavored and presumptively unconstitutional. (Hurvitz v. Hoefflin (2000) 84 Cal.App.4th 1232, 1241.) "In the case of a prior restraint on pure speech, the hurdle is substantially higher [than for an ordinary preliminary injunction]: publication must threaten an interest more fundamental than the First Amendment itself. Indeed, the Supreme Court has never upheld a prior restraint, even faced with the competing interest of national security or the Sixth Amendment right to a fair trial."
Re: limitations on 2nd Amendment
In essence, Emerson, and the district court, concede that had the order contained an express finding, on the basis of adequate evidence, that Emerson actually posed a credible threat to the physical safety of his wife, and had that been a genuinely contested matter at the hearing, with the parties and the court aware of section 922(g)(8), then Emerson could, consistent with the Second Amendment, be precluded from possessing a firearm while he remained subject to the order.
These, and supporting texts, make it clear that sections of the Bill Of Rights may ONLY be suspended in very deliberate, targeted, individual cases where specific evidence is approved by a judge in a federal court - IF they may be suspended at all. Broad suspensions based on nebulous fear, as you suggest for the 4th Amendment, are not Constitutionally acceptable. Bare baseless fear that someone might carry a weapon onto an airplane with the specific intent to commit a heinous crime does NOT warrant federal agents suspending the 4th and 2nd Amendment rights of passengers.
If you still disagree and hold to having federal agents check everyone's luggage, PLEASE demonstrate a clearly Constitutional basis for suspending one of your Constitutional Rights.
Actually, I'd like to see the feds take over airline security screening - specifically so the issue can be taken to court and such warrantless searches struck down once and for all.
Again I disagree, there are several instances in which citizens entering what are considered public institutions have been legally searched because of security concerns. Those entering the Pentagon, for example, are subject to the same search procedure as one finds at an airport. Even those taking the White House tour are subjected to a metal detector screening.
Actually, I'd like to see the feds take over airline security screening - specifically so the issue can be taken to court and such warrantless searches struck down once and for all.
I don't think that the security would be struck down. It is still illegal to carry any sort of weapon onboard an airplane. Since there are still those who attempt to carry weapons regardless, it is necessary to keep up some kind of security force.