What will happen if most of the miners in the bitcoin network are cheaters — or the bad guys? That really does not matter given that all those bad guys do not work together. But, in case if all those bad guys work together or in other words, at least 51% (more than 50%) of the total computational power of the bitcoin network is owned by one or a single group of miners, that’s not a healthy situation for bitcoin. In practice, it’s a huge investment to gain 51% of the total computational power of the bitcoin network. Let’s say someone still does it — what would happen next?