What are the consequences for simply refusing to obey a crew member's instruction to power down your Kindle? Sort of like willfully ignoring the distinction between the first-class and economy security lines---something I wish more people would do.
There's two Federal laws at play: one that requires crewmembers to tell you to power off the device (FAR 121.306), and one that requires you to comply with an lawful instruction given by a crewmember (49 USC Sec. 46504) (Since getting you to turn off the device is a crewmember duty spelled out by the FAA, your refusal to comply falls under "lessens the ability of the member or attendant to perform those duties". Intimidation seems to be broadly interpreted in courts as meaning anything other than cooperation. It doesn't matter if you refuse politely).
Thus the potential consequences are: you can be fined under title 18, imprisoned for not more than 20 years, or both.
Disclaimer: IANAL