EDIT:
"I bring dumbphones when traveling because battery lasts two weeks, unlike iPhone"
"I heard that there are lot of thieves in the country I visited, so I was afraid to bring my real phone"
"I heard that airport X-ray machine can brick iPhone"
"I really like cheap, Chinese phones, they are so cute"
"iPhones are for hipsters, I prefer cheap, practical devices"
possibilities for excuse are endless. And, as the old rule goes, the stupider the excuse the better - if you can convince CBP agents that you are harmless idiot you win.
This is my main phone I use when crossing constitution-free zones.
> it's a felony to lie to a customs & border patrol officer
That makes me livid: "Oh, sorry, the constitutional laws (that apply to us) don't apply here, see it's not technically the US because reasons." [lies to officer] "FELONY!".
me: "no it's not"
I don't claim "all laws go out the window". No clue how you reached that conclusion.
Remember they're not just dumping the contents for analysis, but also installing a rootkit, assuming the phone isn't already rooted, so once it leaves your presence or they plug anything into it, its no longer a trustworthy device.
Something I don't understand is the postal system is essentially wide open for transportation of drugs and stuff as per numerous dark web stories, so simply putting the phone in a box and mailing it would seem to reduce the chance of anyone in the .gov accessing it down to roughly 0% odds.
I'm convinced most of these stories are submarine marketing by big internet companies that have a wide open door to the NSA as most of the discussion revolves around the government not accessing your "private" Facebook activities where no such situation could possibly exist, so there's no point in not unlocking the phone. Ignore the man behind the curtain providing the NSA root privs on the server, the problem is individual officers gaining access to your CRUD app end user device LOL.
Given that the government already has all the data, the real battle is you are trying to appear to be an individual in their database and they'd like to know exactly who, which makes it about as nefarious as asking for your passport, and they know and understand that, so they freak if you won't give them access. As an analogy they know they have all the data on your drivers license and if you refuse to show them your drivers license that will make them extremely interested in why not, you claim you're j random hacker and you claim thats j random hackers drivers license and we have all the license data for j random hacker now why won't you show it, perhaps you have a fake ID for j random hacker or you're someone else trying to set up j random hacker or ...