I never cheated on tests but I certainly saw a lot of it in high school. There was one class where the teacher gave a pop quiz every Wednesday. The problem was that he gave the same exact test for two periods in a row. Someone from the first period would always forward the answers to the next one. When I would get to that classroom on Wednesdays there would always be a group of kids huddled at the back passing around the answer sheet. I wonder if he ever noticed that the second period class always tested better than the first.