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A big red button to smack is the best. ...

Now where you'll be screwed is when the A.I. becomes aware of this button and configures alternate power routes to keep the power on while deploying hostile armed protectors, aka terminators. ;)

Hmm.... OK, then I propose that the Laws of Robotics be amended to add - #1 Law.... "Though Shall Not Mess With The Big Red Button!"
 
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