Are you claiming TPB is not commercial because the person sending the file is not charging the person receiving the file, in a relationship facilitated commercially by TPB?
Somebody making money off of aiding a legal noncommercial sharing doesn't make the original sharing commercial and illegal. Again, compare dating.
And if you can make money off of people wanting to share culture and knowledge, all the better for you.
Everyone benefits from patent reform, copyright reform, the cost of drugs being reduced, DRM being abolished etc. Why derail those arguments with "and legalize piracy!" when TPB etc's perhaps illicit business models are of no lasting consequence to anyone but the few whose pockets they line?
Also, it's pretty easy to judge when file-sharing is commercial - whenever it is done by a commercial entity, e.g. a for-profit radio station that would otherwise have to pay public-performance fees.
The analogy with the postal service made earlier was actually quite apt.
Cheers, Rick
The line between "aiding file sharing" and "file sharing is their business model" is also very, very questionable. We all saw what happened to Mininova when they stopped "aiding".
TPB could easily run without ads. In my mind adding ads to something should generally not affect legality.
A guy who prints DVDs with movies on them and sells them on the street is a commercial pirate. A guy that takes DVDs someone else made and brings them to people is a courier. It's not a very complicated distinction.
The commercial nature of the site affects whether it falls under non-commercial file sharing the OP would like to see legalized of course, in which case it changes the argument from "legalize non-commercial file sharing" to "legalize commercial piracy".
If it is legal for you to download a file and burn it, it should be legal for you to hire someone else to do that for you.
On one hand, it might be legal, deciding the agency is in the person submitting the link and the other person is only automatically shoving some bits around.
On the other hand, you might decide that that's not a service that can legitimately be paid for. Some things can't be outsourced. I think right now that it's legal to 3d print a rifle but it's not legal to have someone else print it for you (but I'm having trouble finding references).
Either way, the intent of the law matters, and it's possible to outlaw commercial enterprises based around piracy but not individuals' actions. One method might be to limit the number of 'uploads' to a number like 10.