I think their quasi-public status means that contracts of carriage should be tightly hemmed in by law and not have as many degrees of freedom as ordinary contracts, but they are still contracts regarding the use of private property, and in the absence of such hemming, the terms and conditions still apply.
If you want to launch a public campaign to change the law and add "you can always surreptitiously record people on airlines" to the set of unenforceable contract terms, go ahead and attempt it. You'll deserve the furious blowback you get, though.
If you want to launch a public campaign to change the law and add "you can always surreptitiously record people on airlines" to the set of unenforceable contract terms, go ahead and attempt it. You'll deserve the furious blowback you get, though.