Cryptocurrency is a type of digital money that is not controlled by any government or bank. It can be used to buy and sell things online, like regular money, but it is even more difficult to trace because it's not physical money. Criminals like to use cryptocurrency because it is hard for law enforcement to trace the transaction, which helps them hide the money they have gained from illegal activities. Another reason criminals like cryptocurrency is that it is not connected to any one country, so it is harder to trace who bought or sold what. Although cryptocurrencies are not anonymous, they can help criminals keep their activities hidden because they do not have to use their real names or banks to make transactions.