concerns arise about the possibility of Bitcoin being used by criminals because of its nature which can be spent on personal payments and can not be undone. However, this opportunity is already there with cash and bank transfer, which has been used for a long time. The use of Bitcoin will certainly follow the same rules that already exist in the current financial system, and Bitcoin will not hamper ongoing criminal investigations. In general, new breakthroughs are usually considered controversial before benefits are fully understood by the public. The internet is a great case example to illustrate this point.