It's still an excellent idea to power off your phone whenever you are in the vicinity of a border guard and never voluntarily unlock it anywhere close to the border. You can't (generally) be compelled to unlock your phone but you absolutely can have an unlocked phone grabbed out of your hands by a border guard with no legal right to lock it.
I believe it's 100 miles from the border including coastlines but does not include a 100 mile radius around international airports. I don't remember the source but Ive seen a map that represented it that way.
Also worth noting, this ruling only benefits citizens in that specific district, as other districts aren't bound by its rulings. Personally I'd recommend having a 2nd device you can use to record your interactions because if they violate your rights your chances of getting their body cam video of it aren't great.
This is important - power OFF your phone. Your phone is more secure before you unlock it for the first time after booting. Use a strong password as well.
You can also force your device into Lockdown mode, which does the same thing, without needing to shut it down or restart it. It's easy to do quickly once you know how.
On Android it's enabled by default, you just hold the power button and press Lockdown.
Iphones have a way to disable biometrics as well with a button combo, but its more a side effect of activating Emergency SOS, not a dedicated feature and how you activate it varies depending on your device model.
They tried to search my laptop when they went through my car at the border, and were greeted with an encrypted boot screen. They tried to interrogate me twice. Glad to know nobody else will have to deal with that now.
"So, you're a tech guy, huh? I bet you're smart."
😐 ...
"Are you into politics? Who'd you vote for?"
🫤 ...
"I'm just trying to have a friendly conversation with you."
🤐 ...
Travel with a burner, wipe it before boarding . If at any time my phone has been removed from my possession, when I arrive back at my home port/airport, I remove the SIM and drop the phone in the garbage.
Laptops I mail the encrypted drive back home and travel with a clean install on a disposable 128/256g drive.
I prefer to send electronics to e-waste recycling (or reuse for some task where security doesn't matter) rather than a landfill, but I'm with you in principle: If the authorities get it out of your possession, the hardware is compromised.