Students are definitely not forbidden from using version control. In fact, version control is encouraged. What they are forbidden from doing is making their repositories publicly viewable.
You are making a large assumption here. I have never seen this be explicitly forbidden in any syllabus nor student conduct code.
You can do a search of their "Honor Code"[1] for the keywords --- "online", "post", "distribute", "share" -- none are even mentioned.
I'd like to be proven wrong -- but this just seems like a fallacy. Posting code online is fine -- copying it and passing it off as your own is not.
[1] http://cs.illinois.edu/current-students/undergraduates/polic...
Laws (and I'm considering honor code policies to fall in that category) are not programs. They intentionally have some ambiguity so that humans can interpret the meaning. Here, the intent is clearly that students should not share their work. They need not explicitly forbid all forms that such sharing could take.
"As described in the Student Code, aiding someone else's cheating also constitutes cheating. Leaving your program in plain sight or leaving a computer without logging out, thereby leaving your programs open to copying, may constitute cheating depending upon the circumstances. Consequently, you should always take care to prevent others from copying your programs, as it certainly leaves you open to accusations of cheating."
That seems like a student's issue -- not the University's. Give an in-class closed-book closed-note exam and the students who did not bother to actually learn the subject will fail.
> I stopped this practice when I got a 0 on a major bit of coursework (cost me a grade boundary in my degree...), as their software found it online, on my site, and they refused to view my work as anything but plagiarism
It seems you did not fight this hard enough. It would be easily proven it was your work and posted after you began work on the assignment. It's actually customary now at the local University by me for the professors to encourage use of Github and the like.
In the end -- the University might "own" copyright over the exact phrasing of the questions that spawned the code solutions -- but they do not own the solutions themselves.
Actively forbidding students from learning and using version control is egregious.
The argument that other students might plagiarize so all the code solutions must come down is simply ridiculous.
I'm also upset that Github redacts the contact information from the DCMA Takedown requester. Students should have an option to directly contact the individual at their University and challenge this.
There are a lot of people in this thread stating that students are not allowed to post homework solutions online and therefore this is fair -- I have never seen in any syllabus nor student conduct agreement anything forbidding posting of a student's own solutions online. A lot of student code is online - and sometimes is even used as part of their first resume after university to land their first real job.
Posting homework you did and own copyright of online is not breaking any rules. It's breaking rules to copy/plagiarize that code and attempt to pass it as your own.