Bitcoin control by nobody but everybody could earn bitcoin with mining using PC (CPU or GPU) or Other hardware with higher hash rate to increase the mathematical problem solutions which will produce bitcoin as the reward..!  Bitcoin is stronger than other currencies because it prevent corruption due to only limited bitcoin will be produce at certain time, but other currencies which relied on banks exposed to corruption because banks are printing money and the cost to produce $100 paper lower than 50 silver cent. Hope it make sense..! Million of Thanks to Satoshi for Invented Bitcoin..!