It is already happened. Bitcoin. Bitcoins are like Freenet or Tor. The extremely aggressive and invasive actions required to take any of them down will result in small gain together with large protests. Decentralized and open source networks cannot be taken down. Probably after all governments have leaned something.
You can trace to some extent you cant trace origin of something made from 0 and 1. Something has te bo behind it,, u cant simply make money out of anything, right?
Protests? Do you really think that will stop government to do anything if they chose so? They have taken down megaupload, they can take down anything if they chose to do it