Drawing a line of distinction on Lecture materials and papers for publication and attaching appropriate level of usage are primarily important.

I agree with Olaniyi Felix Olayinka's view, there should be a strict use for course material and only for academic purposes.

Best regards

Mhd. Syahnan

I do not know how to handle the intellectual protection law of your country, but in Mexico there are two entities, the Mexican Institute of Intellectual Property, which protects patents, trademarks, industrial designs among others, and the second entity is the Indautor, this entity protects copyright and I think it is the best way to protect literary, artistic works as well as manuals.

I'm a former academic researcher and current Intellectual Property lawyer who is doing a part time MSc course. Whilst I can give you the text book legal answer in terms of copyright and contract law, - essentially the author owns the copyright in all substantial and original works - and copyright arises automatically when the work is made - unless there is an agreement (like an employment contract) which means that someone else (like an employer) owns the copyright.

But I suspect that that answer is not of much practical use to you. The the first things I would ask a client who came to me with a similar problem is "what do you want to achieve?" Are your economic rights threatened by this unauthorised sharing (are you or your institution loosing money because of it? is anyone else making money from your hard work) . If, as I suspect, money has nothing to do with it, then you probably want a solution which doesn't cost you money (and suing someone or instructing a lawyer will cost you money). If what really bothers you is the breach of academic curtesy in failure to have your hard work acknowledged then the law will probably not be part of the solution. They are your students and it is your (and your colleague's and institution's) responsibility to educate them as to academic norms. Make it clear to them that they are not to post stuff without acknowledgement or permission (make it clear which they need to obtain). You can reinforce that message in the documents themselves (stick your name in the header or footer of every page - "copyright, date, name, not to be copied or shared without permission") and correct them when they get it wrong. Most people behave properly when asked to do so, but plenty of people need to be asked.

if you see material on platforms that you want to take down then depending on how legit the platform is you could ask them to take it down - simply explain that it is your course material and that you (or your institution) own the copyright and ask for it to be removed. Sometimes that works. It does not harm to ask. Good luck