Metaphors and similes are used to add depth and meaning to the poem, so it looks normal on the surface but when you re-read it you uncover a deeper meaning :)
You would use a comma. The semi colon acts when both what is in front and behind it can stand alone as a sentence. “With technology in the hands of so many people” does not make sense standing alone.
The air we breathe that is the answer I believe it's right
