Existing outside of the realm of traditional finance and with no central point of authority, digital assets have posed several challenges to governments worldwide.
https://cointelegraph.com/news/no-tax-for-you-why-crypto-traders-and-miners-might-head-to-portugal
https://cointelegraph.com/news/no-tax-for-you-why-crypto-traders-and-miners-might-head-to-portugal