Absolutely. In fact, every educator I know has had the discussion that "yes, you can copy wikipedia. No, you can't say it is yours" with a student at some point. It is a point of occasional confusion with students, but absolutely not with teachers.
That said, I can easily see a standard being included in common core that says "Students should determine the copyright status of any work being quoted, to ensure ownership is maintained." Once that is in there, every teacher is going to be searching for planning materials on how to teach that standard. Without it, teaching materials are going to rarely be utilized.