I'm a very observant person, always sit in the back of the classroom because I find it to be the most comfortable and it always allows me to see everything ppl are doing (i dont sit in the back for that very reason). I've noticed quite a few students cheating on tests, I never say anything at all. I tend to notice that the students who always schedule classes with their friend/siblings and sit together in every class tend to cheat on quizzes a lot. I don't know how the professors don't see this. In one of my classes, four students who were all friends would always sit together in class and you could obviously see them passing over notes and looking at each others tests on the exams. I never said anything, didn't feel it was my place. The teacher even started to notice and the only thing he would say was "look at your own exams" over and over again.
Anyway, when you see students cheating do you feel the need to let the professor know about it? or do you stay quiet & figure they'll eventually meet their own unfortunate fate and get caught?