[rodonn]

If you had a system that was (a) oriented towards achieving some goal and (b) understood the world it was operating in, then allowing someone to "pull the plug" would interfere with it achieving the goal it was trying to optimize towards.

There has been some attempts at researching the question of how to design a intelligent system that is "corrigible" = willing to allow humans to change the goal it is set to optimize. This is unfortunately still an open question where no great solutions have been found that seem to be reliable when faced with a highly intelligent and capable AI system.

If you are interested in reading more, a few relevant search terms are "Off-switch game" and "corrigibility".