They can request your PIN all they want, but you are not obligated to provide it. They can temporarily detain you but not indefinitely, and the EFF is challenging their authority to even do that. [0]

Personally, I would refuse to unlock my phone. My privacy and upholding civil liberties is worth being detained for a few hours (or even days).

[0] https://www.eff.org/press/releases/eff-aclu-media-conference...

This only works if your lawyer is with you or you're white.

Why would you have your lawyer with you? Better to have them outside of the range of border control agents (remote) so they don't get arrested too.

Does this work for non US-residents e.g. tourist, conference, etc? Or do they politely show you the way out (the country)?

No, if you're just visiting they can ask for whatever they please.

An important point: the would likely confiscate any devices you refuse to unlock. Is it worth that?

Yes. They are supposed to return it eventually, and even if they don't I'm willing to pay $1,000 to protect civil liberties.

Amen!

Also, the border is 100 miles from the Mexico/Canada borders and 100 miles from the shore. So, if you're concerned it's not when you're entering or leaving the country. It's any time you're in LA, NY, DC, SF, Huston or Detroit. Or any of the other thousands of miles of border.

Common misconception: If you have crossed the boarder, then within 100 miles of it they can search you.

Of course, how you prove you didn't cross the boarder is an open question. But you can in fact refuse the search on that claim. I suppose they may detain you then.

I think you're looking for the phrase `probable cause`. If the officer has probable cause to think you crossed the border, they can search you. I'm not a lawyer, but i think they can search you anyway. It just won't be admissible in court.

edit

to clarify, US law pushes police right up to the edge. there is a preference for false positives rather than false negatives. it's more important to catch all of the criminals than it is to inconvenience some innocent people. The risk of letting one criminal go is much more than cost of detaining a doctor for a couple of hours.

Now, we're in this weird time where that doctor can have 20 years of hippa protected medical records in their pocket that they might be forced to disclose. Historically, that doctor may have some records in a briefcase, but not tens of thousands.

There are inland checkpoints, even on the Canadian border that search people who've been in the country for a while: http://www.washingtonexaminer.com/border-patrol-checkpoint-i....

They can even nab American citizens for drug possession:

"One of the people arrested was a U.S. citizen who fled the checkpoint and led the police on a five-mile chase. The unnamed man was arrested and charged with three felonies, including reckless driving, possessing a controlled substance, and endangering the welfare of a minor."

I read that they are not able to force you to provide a pin.

But even if you're right, this doesn't change my argument. Most people are less secure most of the time in the absence of biometric authentication. Because without it, they will opt for zero security. You can always use the pin in addition, for whatever that's worth.

You know what would be really neat? A different, restricted/camouflaged unlock when you make a slight facial expression that would probably go unnoticed.

regular face: regular unlock right eyebrow raised a tiny bit: hide my sensitive stuff from a casual search*

*and after a few minutes, if I don't deactivate it, start deleting.

Unfortunately, lying (including fraudulent representation) to a federal agent is a crime (https://en.wikipedia.org/wiki/Making_false_statements).