What are your rights if U.S. border authorities ask for your phone?

I love the spirit of what you're saying, but per the attorney's advice in this article, they might seize your phone no matter what you say, password protection with no fingerprint or face scan unlock should ideally keep them out (note that law enforcement usually can take your picture or finger print you without needing a warrant or anything, but they can't force you to tell them a password), but you will probably never get that device back and you could be detained indefinitely while they try to intimidate you into waiving your 5th amendment silence rights.

So because citizens have an absolute right to reenter the country, they have a bit more leverage to, you know, deny a request or refuse to comply with requests to unlock their phone. But that doesn't mean that there aren't going to be consequences. They could be detained for several hours. Their phone could eventually be confiscated. So even U.S. citizens have to think about those potential consequences.

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[As for lawful permanent residents,] [t]echnically, they also have to be let back into the country, but as we've seen in sort of a nonborder contexts, the government and the current administration is pretty willing to question the status of LPRs. And so we always say that, you know, they should be especially kind of mindful and thoughtful about how they comport themselves at the border.

I think your best strategies would be 1) just do not travel to the United States if it can at all be avoided; 2) if you must to travel to the US, don't bring any electronic devices capable of storing media with you, purchase new ones after you are past the border, securely download what you need, then erase and destroy those devices before leaving; 3) if purchasing throwaway devices isn't an option, just act as white as you possibly can and just hope you get lucky and they ignore you.

As an American -- please don't come here until we've sorted our shit out. Money is frankly the only thing these morons will listen to.

because I'm sometimes too literal, you mean a surveillance bug, not an insect bug?

wipe phone

I'm not convinced there is any way to reliably wipe private stuff from a phone. You have to have a separate phone for travel purposes. Buy it new and never let anything really private onto it.

Great advice, but what if you're concerned about the possibility that you might be stuck in the other country permanently(not because of the search itself but because the U.S. Government could fall apart while you're visiting the other country)?

Do you just give up on having your phone?

Or you know, fix the country? Isn't that a better way to deal with this problem instead of band-aiding every single thing?

If you don't want to disable biometric auth, familiarize yourself with your phone and see if it has lockdown mode. Apple phones and most modern Android phones support it, using it will require your password / pin for unlocks. Put it into lockdown mode for the flight.

This all assumes you’re a US citizen. While technically it applies to all people, the current administration has had no blowback for consistently ignoring these laws for non-citizens.

Best thing you can do if you absolutely need to take your phone across the border (eg, you need your MFA) is to remove any biometrics, change the password, turn the phone off, and if ordered to enter the password, honestly say that you changed it just before traveling and have now forgotten it.

Personally, I find it easier not to travel to/through the US than to buy a burner or wipe/restore my device (I’m not going to stick my data on cloud backup).

You're better off turning the device off entirely. Lockdown mode doesn't put the device back into a BFU state so you're still leaving room for an exploit from Cellebrite or Greykey. Not having that first unlock after you turned the device on gives them a shitload of problems.

Lol you will get this then with that attitude