Since Rean had specially selected a thousand people who seemed to have little to no attachment to this world, the final answer was pretty obvious. Of the one thousand, over nine hundred of them already had their answer even before a single minute had passed upon their return to Earth. The next 72 hours were basically used to settle their personal issues.
Well, many things happened during those 72 hours. First, Rean never really tried to hide since he showed himself and the people floating around Pluto on purpose. That said, once those people who appeared in the images returned to Earth, most of them were taken into custody by their governments. After all, what they had seen and experienced was literally 'out of this world.'