Cryptocurrencies (or cryptos) captured the world's imagination during the last couple of years. From their spectacular rise in 2017, to their equally hard fall in 2018, and to their most recent revival this year. Cryptocurrencies and the blockchain technology powering them are regarded as disruptive forces, proposing an alternative decentralized monetary system. They have also gathered their fair share of criticism. Cryptocurrencies are accused of facilitating transfer of "dirty money" between criminals. They provided mind-boggling returns a couple years back and earned the reputation of being a "get rich quick" scheme.