Using an iPad or iPhone to mine bitcoin or other cryptocurrencies would be hard to do, as the CPU power available to complete the task would be a drop in the bucket compared to what's needed.But using a portion of the CPU power from thousands of iPads or iPhones to mine cryptocurrency makes more sense & and that's exactly what some malware has been doing.Apple is now moving to stop the practice.[ Further reading: The way blockchain-based cryptocurrencies are governed could soon change ]