You power cycle the phone and you'll need to enter the PIN before you can use Touch ID.

You'll also need to enter the Apple ID password the first time you try to use it (in the iTunes Store etc) after a power cycle, too.

The SIM doesn't participate in device security, although I could of course set a PIN on that too.

If you half inch the SIM then you can use my data, I guess. I have unlimited calls and texts.