I'm not 100% sure. I do know that sets of questions are able to be DMCAed, so solutions to problem sets are likely to fall under that, though IANAL. I have work

I'm not 100% sure. I do know that sets of questions are able to be DMCAed, so solutions to problem sets are likely to fall under that, though IANAL. I have worked for a company that took down answers to such questions in response to a DMCA. Our lawyer pointed out a specific clause that made it risky. In almost any DMCA case, there is some set of case law that backs up one side or the other, and all you're doing is deciding whether you think the content is valuable enough to go to court over to protect. It's usually not worth going to court over :/ To be really tested, it'd have to go to court. I noticed when searching a lot of solutions were still up for this course, so maybe the solutions alone are OK, and it's only the base code being DMCAed. That said, there is a lot of base code still up too, so it's likely that this person just hasn't come around on their whack-a-mole cycle yet.