I've heard more than one person say if you're going to have to surrender your phone, if there's even the risk of it, turn it off.

Yup:

https://twitter.com/SwiftOnSecurity/status/72679792664774656...

https://twitter.com/SwiftOnSecurity/status/72679736451038822...

If you turn off your iPhone, you can't use it again without entering your password, and you would have to do that consciously. On the other hand, your phone could otherwise be unlocked with just your fingerprint.

Is there a way to know Touch ID is available, but can't be used because the device was just rebooted? Or does it act like there's just a password?

>Is there a way to know Touch ID is available, but can't be used because the device was just rebooted?

I don't know the verbatim message, but it says something along the lines of "Passcode is required to enable Touch ID"

"iPhone requires your passcode after restarting" vs "Touch ID requires your passcode when iPhone restarts" Also, if Touch ID is disabled then putting a finger on the sensor does nothing, but if it's enabled it shows the passcode screen with the above message

Edit: with Touch ID enabled, if you slide to the lock screen without touching the sensor, it says "iPhone requires your passcode after restarting" but the title says "Touch ID or Enter Passcode"

At the very least, use the wrong finger 5 times on the sensor and it will disable the Touch ID.

And risk being charged with obstruction. Like perjury, it's naturally difficult to prove, but one should be aware of the risks before moving down that course.

No, I mean, disable Touch ID before any potential situation where the phone might be seized for any reason, not after a judge had ordered you to unlock the phone with a thumbprint.

The moment you believe the phone is going to be seized by law enforcement and you act accordingly to make it more difficult or impossible to retrieve data from it, you are guilty of spoliation / tampering of evidence. This is the same set of laws that makes it illegal to shred papers before law enforcement can get to them. Locking or erasing your phone is simply the digital equivalent.

Couldn't you also apply this argument to everything? The client turned on full disk encryption 5 years before this arrest because he wanted to make it difficult for anybody (including law enforcement) to read the content of the disk.

I think you could just argue that you didn't want the disturbed and/or wanted to save some battery.

> Couldn't you also apply this argument to everything? The client turned on full disk encryption 5 years before this arrest because he wanted to make it difficult for anybody (including law enforcement) to read the content of the disk.

No. The difference is that the action is taken to obstruct a specific investigation. Generally protecting information without regard to a specific investigation is not obstruction. Same as shredding papers years before they become relevant to an investigation is also not obstruction.

> I think you could just argue that you didn't want the disturbed and/or wanted to save some battery.

Like perjury, proving obstruction may be difficult. That doesn't make it any less illegal.

"I just turned it off since the battery wears down really quickly and I thought I might need it to make a call later."

Difficult to prove.

Difficult to prove and illegal. Like lots of things.

Since when is turning off your phone illegal?

Any muppet attorney can come up with a hundred reasons why this was a perfectly reasonable thing to do.

Illegal to turn off the phone before the TSA checkpoint?

Or, 'remove' your fingerprint... (from your finger)

Correct that you cannot be compelled to unlock your phone (with a code, not Touch ID) or reveal the passcode?