I have a feeling that if NCSoft had any smidgen of idea that they had the code...they wouldn't have the code.
If they did have the code... Then the best thing they could do is to disseminate it as wide and far as possible.
There are lots of ways... and I doubt NCSoft is going to have more luck killing it once it's going than the FBI/RIAA/MPAA/ETC. have had in the last 15 years.
They would not come after us. They would go after the leaker, and they would be easier to identify than you might think, given the relatively small size of the development team. But even if there was only a 10% chance that NCSoft's legal team was able to identify them and even wanted to take action, would you actually ask a professional game developer to risk his or her career just so you could play a video game? Legal action isn't even the worst thing that could happen. Being blackballed in a very small industry is the worst thing that could happen.
If a dev approached me with the source and asked me to torrent it to the world, I would probably do it but not before first advising them against it. I could do it untraceably because my fingerprints aren't on the source itself, but its really hard to be certain that the files you have aren't tainted in some way. A timestamp that gives access away, or meta data that singles you out. An owner flag on a README file you forgot about, or the IP address of your workstation embedded in that print to PDF you made five years ago. A test part of the tree only you worked on. I've worked the other side of the fence, tracking data leaks, and people always make a mistake somewhere.
People are focused on the player side of this, that we could disseminate the source widely, and we could set up servers they couldn't bring down, and NCSoft wouldn't want to go after us. We're not the problem. The question is whose career and livelihood are we going to risk to get there. That's the problem. If a dev somewhere has the source code, I would not expect them to risk their career releasing it publicly, nor would I ever think to ask them to take that risk. I would tell them that if they did, someone like me has a decent chance of tracking them down.