> In dark corners it keeps whispered that if any one entity gets control over 50% of the mining capacity, they can essentially decide the "immutable truth" in t

> In dark corners it keeps whispered that if any one entity gets control over 50% of the mining capacity, they can essentially decide the "immutable truth" in the blockchain. Having >50% hashing capacity allows you to arbitrarily select which transactions will or won't be confirmed. Additionally you can perform double-spends, that is the most important thing (in my opinion) that proof of work was supposed to prevent. Of course with more confirmations this attack becomes more and more expensive to execute. For details see Majority Attack [0] page on Bitcoin wiki. [0]: https://en.bitcoin.it/wiki/Majority_attack https://en.bitcoin.it/wiki/Majority_attack