Oh yeah if its just basic homework then coursehero and those kinda sources are the problem and to me the bigger problem is a lot of homework is lazy, its just prove you've read the texbook shit. Homework needs to get more analytical.
i believe the oppisite should happen, like take home tests, the professor knows the student is going to open the textbook and copy so make the question such that we are evaluating you to think. if you've ever had an open book advanced math course then you'll have an idea as to what homework should to become with more time window.