He created a website that facilitated a lot of illegal stuff and got wealthy from it. Now, I happen to think a lot of that stuff shouldn't be illegal but it was and still is and it's not a surprise that the government went after and convicted him, especially with Big Pharma not liking the competition and funding a lot of politicians' campaigns.

I don't know how much Trump actually knew about Ulbricht when he made his promise but I wouldn't be surprised to see him slow-walk it.