First of all bitcoins have many flaws  ut can be used in illegal transactions such as illegal drug payments deals from illegal  doings it can be safe to anyone and the criminals and illegal doers as well and some governments of a state dont approve this kind of transactions to make the criminals off the hook it can ge dangerous to other countru too because criminals can use this kibd of method to erase some traces of illegal transactions that has made it cannot be used in other because bitcoin can be used also in wrong doings it is not it is a dangerous activity on a country if not stopped fast