A professor at my university tried that, but the students quite quickly made a huge fuss, got the principals office involved, and the universities lawyers informed said professor that what she was doing was illegal, and that she should stop before she got any more trouble. She stopped.
A professor at my university tried that, but the students quite quickly made a huge fuss, got the principals office involved, and the universities lawyers informed said professor that what she was doing was illegal, and that she should stop before she got any more trouble. She stopped.