You're being pedantic. The point is that there are similar laws regarding conspiracy that are even more broad, that could easily put an exit node operator in prison.
> On the other hand, one who has no knowledge of a conspiracy, but happens to act in a way which furthers some object or purpose of the conspiracy, does not thereby become a conspirator. Similarly, a person does not become a conspirator merely by associating with one or more persons who are conspirators, nor merely by knowing that a conspiracy exists.
There's your defense. An individual running a TOR exit node with the purpose of passing news to people behind the great firewall of China does not become a conspirator because an anonymous individual uses that node to commit wire fraud. They had no knowledge that a conspiracy was being committed - they may have furthered it (by simply running the node) but that is insufficient for a conspiracy charge.
> Running a TOR exit node almost certainly would not constitute an agreement under federal law.
You may very well be right. All I'm saying, and this is the EFF's position as well, is that at some point a prosecutor (or several) will test this. By running the node, you have agreed to have traffic run through your system. Given the shady reputation, you are saying "come do illegal things with my internet connection, I'll protect your identity".
Federal prosecutors are smart, and most are gunning for jobs at high-end law firms. Someone is going to try to get a nice resume bump by testing this eventually, and there will be an unlucky exit node operator that will at best only have to pay a six figure defense bill, and at worst will spend time in prison.
If that were really "all you were saying" the comment thread wouldn't be so deep. But earlier you said, "that's enough to make someone culpable," implying not that a prosecutor would test it, but that someone would be convicted. There simply isn't a sturdy argument for that proposition.