I don’t know about the history of the world, but an author who made an *unpublished* change to software would have inconsequential actual risk of liability or punishment on copyright grounds, if for no other reason than no one else will know or care. (I am assuming the author had a proper license to the original, unaltered software.)

However, if the author later published the unauthorized derivative, and the original licensor or a third-party beneficiary detected that fact and brought suit for infringement, that author’s relevant, internal, unpublished documents, including without limitation working papers, phone records, diaries, and such, is subject to full discovery as a matter of course.

Relevance, of course, is an elastic concept, and lawyers make a ton of money arguing the scope of proper discovery. However, your example assumes that the working papers, etc., are related to the final product. They would be discoverable to show the extent to which the defendant knew about the violation, the extent to which the derivative relied on the original, etc.

Here’s a link to the general rule governing discovery, Rule 26 of the US Federal Rules of Civil Procedure, “General Provisions Governing Discovery; Duty of Disclosure”:
http://www.law.cornell.edu/rules/frcp/Rule26.htm

Here’s a link to Rule 34 of the US Federal Rules of Civil Procedure, “Production of Documents and Things and Entry Upon Land for Inspection and Other Purposes”:
http://www.law.cornell.edu/rules/frcp/Rule34.htm

Here’s a link to Rule 37, “Failure to Make or Cooperate in Discovery; Sanctions”
http://www.law.cornell.edu/rules/frcp/Rule37.htm

Enjoy.

Happy Trails,

Loye Young
Laredo, Texas

However, I would be interested to know of any previous case in the history of copyright in which the author of an unauthorised derivative:
1) Has had their unpublished, intermediate derivatives or other working materials sequestered
2) Has been prosecuted and found guilty of copyright infringement
3) Has been jailed as a consequence

Good example.

Assumptions: To make matters simple, we’ll assume that Jim, Bob, Fred (or significant assets of his) are all in the US or subject to its jurisdiction. Further, because in the USA contracts are usually governed by state law, I’ll assume Texas law, because that’s what I know. Many jurisdictions have commercial laws similar to Texas, so that’s not an unreasonable assumption.

Answer: Yes, Fred can be compelled to turn over the source code before trial, during discovery. Either Bob (as the licensor) or Jim (an intended third-party beneficiary) can achieve the same result, but Jim’s case would have better aesthetic appeal to a judge, IMHO. Bob or Jim can automatically get a subpoena for the code from the court clerk simply by asking for it. Fred’s lawyer will likely try to get a hearing on a motion to quash the subpoena. He’ll lose, but he’ll try anyway because he wants to make a living, too.

Legal Fees: Relatively cheap. Hard to define exactly without some knowledge of the precise facts and the parties’ situations, but on the facts you state, I’d put it in the $5,000 to $10,000 range because I assume Fred’s lawyer will try the low-cost, standard dilatory tactics. (YMMV, significantly) If Fred has actually violated the GPL, as the facts assume, Fred be liable for the legal fees for both sides.

Available enforcement: If Fred were to distroy the source code, he would be criminally liable for obstruction of justice, punishable by incarceration. If he were to refuse to provide the code after being ordered to provide it, he would be jailed for contempt of court.

Conclusion: GPL can compel disclosure of source code, even from one who “doesn’t believe in copyright.” Stallman, et. al, wrote the GPLs to ensure the code stays open to the maximum extent possible. They did a good job.

Note: Your example is a developer who distributed only binaries. I started this conversation by stating that a developer who switches between GPL v2 and v3, or vice versa, would not have much actual exposure. I stand by that argument. That’s because the source code would be open under either license, which is the fundamental consideration of either license.