[neltnerb]

Is source code covered by copyright at all if it's never published? I thought that was the bare minimum.

If they never release the source code at all, I think we're just screwed, legally anyway. The DRM was attached to your binary or stream (or book), not the original source material. We may not like it, but I don't think it's copyright you have to worry about when it comes to closed source code.

[MereInterest]

Under current law, copyright applies to any creative work, regardless of publication status. This leads to abominations such as Disney's Vault, intentionally restricting access to a work that is part of the public consciousness.

In my ideal world, if the source code is not placed under escrow and tested to result in the distributed binary, then there would be no monopoly given to that binary. Anybody is allowed to copy it to the fullest extent that they are able to.