Ever heard of Snowden, Manning, or Assange? (names from the top of my head, but the full list is endless) Besides, if someone (a regular person) were to disappear for being a dissident, you would never find out. And it would fit perfectly the US behaviour in every other matter.
I said "dissidents." All of the above three leaked classified secrets; countries like China will arrest you and subjugate you to inhumane conditions just for criticizing the government, or trying to start political change.