> You modify a car for better speed and handling. Later it gets used to rob a bank. You go to jail.

People modify cars for speed all the time. Most of them hoon around tracks or country roads, which isn't a crime - or, at least, is nothing more than a traffic ticket.

> You download Tor for a friend of a friend. They use it sell drugs online. You go to jail.

People use software to protect their anonymity all the time. Some just don't like the government, others don't like to respect copyright. Not a criminal matter either way.

> You sell someone a special hunting rifle (out of season). They use it for poaching. You go to jail.

People collect guns all the time. Most of them shoot at paper or clay pigeons or hoon around on the firing range, which isn't illegal.

These scenarios compare pretty poorly to what we've heard the person in this case did: he, for years, aided drug trafficking. In the first paragraph he admits to knowing this - when someone pays you money to install an ultra-secret compartment in your vehicle, and when you pull out nearly a million dollars in cash while trying to fix it, you damn well know what's up.

If I tune your car up, my expectation isn't that you're robbing a bank. On the other hand, if you bring it for repairs and I discover the problem is twenty bags of sequential bills in the trunk throwing off the suspension, my expectation is going to change pretty quickly.

The law isn't a magical thing that you can circumvent with the right incantations, nor should it be. It's better to have this flexibility, not worse.

ED: This is a controversial comment, which surprises me a bit. Let me add I'm not much of a fan of the war on drugs. But my central thesis is that allowing the legal system to apply a dose of common sense prevents such things as mandatory minimums and blind sentencing, which is a good thing all around.

Wait, it's "common sense" to you that we should be sentencing non-violent offenders to 20 years in federal prison? How does that make sense?

What is the cost to tax payers of putting him in prison for 20 years? What did he cost tax payers in helping the drug traffickers move their drugs a tiny bit more effectively? I can not imagine that this nets out positively for society, and it effectively ends this guys productive life.

It's possible to agree with the conviction while disagreeing with the sentence. In this case, no, the punishment is excessive.

But the point of my comment wasn't to address that, but to address the conviction.

These are not equivalent scenarios. They are all one-shot deals and, significantly, there isn't an obvious connection between the sale and the law-breaking. They could probably be altered to match a little more. Here's my take on the third:

You sell special hunting rifles that are designed to kill elephants. Sometimes people need them for self defense, you say when people ask. You insist that purchasers not mention that they will use them to hunt protected species, especially elephants. One of your clients asks you to come out to the field to repair his gun. While there, you see a stack of elephant tusks in the back of his truck. You tell him to get them out of there. Then you sell him and his friends more guns over the next year. They are caught and convicted of poaching, and then you are too.