https://techcrunch.com/2017/08/17/an-ios-11-feature-could-let-you-quickly-disable-touchid-and-keep-cops-out/

TouchID has always been a legal grey area when it came to cops and border patrol asking you to fork over your phone. But, with the new update in iOS 11, that no longer seems to be a problem.

The new feature is being referred to in some circles as a “cop button” because it allows the iPhone owner to set up a provision in the update allowing you to choose whether to keep TouchID on or not. This allows travelers and people who tend to get harassed by police more often — or just anyone concerned with privacy and security — to set their phone up using a long, complex password, thus locking out cops and anyone who doesn’t know the passphrase.