What would happen if an army of hackers put America's power grid in its sights and pulled the trigger? How fast would the country descend into darkness? Would there be anarchy in the streets? Would people die? According to a war game carried out across the country this week, the answer is not necessarily good news.
I can't figure out the meaning of in its sights in this sentence.
It refers to an intense focus, and as mentioned above, through the scope of a weapon. It implies that the entire problem is being viewed and processed in great detail. There is an assumption that a solution or more information will be provided and the person who is focusing is in a position of power to control the situation.
in its sight, as for that sentence, means as their target, as far as i know. It fits quite nicely too, "What would happen if an army of hackers put America's power grid as their target and pulled the trigger"