Perhaps they need to start periodically saying things like "just a reminder, this video is from <University of XYZ> and is copyright by us" and periodically scr

Perhaps they need to start periodically saying things like "just a reminder, this video is from <University of XYZ> and is copyright by us" and periodically scribble that on a whiteboard too. It may make the class sound a bit silly at times but we live in a world where plenty of people are just fine with making blatant copies of things. I am against DRM. I don't think it helps anyone to hide content behind buggy technologies, especially when they cause problems that have nothing to do with protection such as security holes. I think you just have to modify the content itself; make it "hard" to cleanse every last mention of the true copyright owner, and stop worrying if some loser actually wants to spend the time and effort it would take to strip all of those mentions out.