This, and other comments to the effect of purposely messing up your fingerprint to force PIN/password entry, are all technically effective. However, if you perform any of these actions after an encounter with law enforcement or the legal system has already started, it strikes me that your actions could be interpreted as destruction of evidence. IANAL, though.

Even using a PIN over a fingerprint is enough to piss off the FBI by making it more difficult to get in. If you're unlocking your iDevice with Touch ID only, you should consider your device insecure against even undetermined law enforcement.

It would be obstruction, not destruction. The evidence still exists, but you took steps to prevent law enforcement access to it. Destruction would be some sort of kill signal to the phone when they ask you to unlock it.

>It would be obstruction, not destruction.

It is obstruction in the same way that requesting a warrant before handing over evidence is obstruction.

Your comment is purposefully obtuse and meaningless. Obstruction via exercising your 4th amendment right in the US is legal, because that's what being a right means. Refusing to comply with a court order to unlock your phone is still illegal.

PIN Code is also required when you fail to authenticate with Touch ID five times. So one could use the wrong finger a few times and that would solve the problem ;).

I've noticed that Touch ID is super brittle (at least on my own iPhone 5S), too. If your finger's slightly wet, that may be enough.

Indeed, trying it now, if I lick my finger and then use it to try and unlock my iPhone a few times, it disables Touch ID and requires a passcode!

Unless you are prepared in advance, after they take your phone you likely won't have the chance to turn it off.

There should also be a timer that puts the phones into require-password mode. So after a few hours they'll need more than a fingerprint.

Maybe you should also have the option of setting up a "coercion fingerprint(s)", which if used to authenticate would put the phone into require-passcode mode. Then, if the court compels you to unlock your phone with your fingerprint, you can put yourself back into 5th amendment territory.

Actually, in that last case, you might already be protected. If 9 if your fingers will force your phone to require a passcode, and only one will unlock it. Could the courts/police force you to disclose which finger is the one that unlocks? I'd imagine you could put them in a situation where they have to chose which finger you use (or manipulate your hand themselves) to perform the unlock action, and in that case they'd only have a 1/10 chance of actually getting what they want.

There is- after 48 hours iOS will require the PIN again to enable Touch ID.

I shut off my device before every security checkpoint (i.e., airports) or whenever I get pulled over. Only takes a 5 seconds - inconvenience is worth it.

It's also disabled after 48h from your last TouchID login. I'm surprised that this order can be compelled in such a short timeframe.

This was a search warrant issued at the time of her arrest (within less than an hour according to the article). The woman subsequently pled 'no contest' to the charges and unlocked her phone.

In short, this doesn't mean this is a settled issue - none of this has been tested in court.

Could she have refused and held in contempt for 48 hrs? After which she could no longer be held in contempt?

Legal niceties take much longer than this. Once 48hrs is passed your fingerprint is useless to unlock the phone. At that point there is nothing they can do since they cannot demand you give them the code. A finger is part of your body, the passcode is only in your head.

Which is why I'm still wondering how this decision even helps...

This wasn't a decision - it was simply a search warrant that included the demand. It's not a legal precedent or case law...

In most cases, you won't have the time. SOP in law enforcement raids is to secure their victim prior to securing anything else.