There is a strong opportunity for the right blockchain-cryptocurrency solution to solve this problem.
How? If the banks start opening up to the cannabis and medical marijuana industry then users can buy them legally with fiat and credit cards. Thats where BTC and other cryptocurrencies lose their notoriety as the preferred medium to use for buying and selling illegal drugs.
Regulations and restrictions give more value to BTC than we know.
While the money changing hands in the dark net is big, it is not as big in terms of percentage as it was years ago, now many people are doing legitimate business and activities in bitcoin, many people in the forum are against anything that is black hat or illegal and you are going to be banned or given negative trust if you even suggest to do something like that, and that is the general attitude of bitcoin users, we want to distance ourselves from those people.