He did nothing wrong, he never handled drugs directly, he just acted as a medium for the crime to happen, the US government allows for hundreds of people to die each year, do we see Obama being thrown into jail?
but honestly, he is probably gonna get life in prison
Not entirely true. In fact, Ross was actually the first drug seller on there. He grew some Magic Mushrooms and used them to get the Silk Road going as detailed in his writings found on his computer.
But they need proof, not only some letters in his computer..
Sorry for picking on you, but a lot of people have problems with what constitutes "proof" and "evidence."
"Evidence" is a term of art. Evidence can be "direct evidence," or "circumstantial evidence." Let's say Defendant Dave is charged with murder, specifically killing Victim Valerie. Witness William sees Dave pick up a gun, aim it at Valerie, and shoot her. This is what we would call "direct" evidence.
Now, let's say William is in one room by himself, and the door is closed. He hears a gunshot coming from the other side of the door, and he opens it up, and sees Dave with a gun in hand, and Valerie on the floor, bleeding. This is what we might call "circumstantial" evidence.
You can use both direct and circumstantial evidence to "prove" a case, but there is no specific type of "proof" required for most types of criminal cases. Ulbricht's case is not one of these special cases.
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Imagine further, that we have a missing person. It'll be Victim Victor. Victor has been missing for many days. Defendant Daisy walks into a police station, and says she'd like to speak to a police officer. She says that she strangled Dave, she buried him in a park, she brings the police to the park, and shows them Dave's body. Is that "proof"? Sure, it seems to be that a confession corroborated by some physical evidence is pretty good.
Imagine yet further that we have the same missing person. The police search Daisy's house and then find a letter. The letter says, "I strangled Dave, his body is buried in the park, over here." The cops go the park and find the body. Is that enough? Sure, I'd think so too.