It's highly frustrating. I bought a couple of courses which costed me 2.5k+ and seeing them here for a few bucks... Well, I think you can imagine how that feels like...
I'm strongly concidering to notify the content creators regarding these posts...
I encourage this.
Though I would do some background research on the sellers first. The most likely case is that they're anonymous so nothing will come of it.
Alternatively, maybe make a thread in the scam accusation section of Bitcointalk, and some DT members might tag them, or create a flag warning users about them.
Though I wouldn't bet on it. As I said, here on BTT some simple plagiarism is a mortal sin, whereas grand theft is often accepted (so long as it doesn't concern other BTT members).