Answer:
One who has offended the government and has been detained by it
What is something you will never see again?
Before Google, we actually had to physically look things up in this building full of knowledge.
What instrument can you hear but never see?
Where humans breathe liquid.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.