I remember an incident when I was in college. I was a computer science major in a small college, so you got to know all of the other students in your major, at least by sight.
There was this one kid who hardly ever came to class, always asking others for help. It was obvious that he wasn't studying and cutting classes. Once he showed up for a mid term exam and sat next to me. It was multiple choice, and it became really obvious to me that he was cheating off my answer sheet after the first few questions.
So I decided that I would mark the incorrect answers, so if the answer was choice A, it would fill in the circle for B, and so on. After a while, I put down the pencil and pretended to review my answers and acted like I was going to go forward to turn in the answer sheet. This dude then gets up, and turns in his answer sheet. I then quickly corrected my own answers and turned in my sheet.
The next time we met in class, he had an F and I had a B. He was pissed! He didn't understand what had happened at all!

A week later, a bunch of us were taking a break in the computer lab. The same dude comes in and starts complaining how he got arrested the night before. He said that he was drunk and used a black powder pistol to shoot out the front window of a store in his neighborhood. He was a class act all the way! After that, he dropped out, we never saw him again.
There was this one kid who hardly ever came to class, always asking others for help. It was obvious that he wasn't studying and cutting classes. Once he showed up for a mid term exam and sat next to me. It was multiple choice, and it became really obvious to me that he was cheating off my answer sheet after the first few questions.
So I decided that I would mark the incorrect answers, so if the answer was choice A, it would fill in the circle for B, and so on. After a while, I put down the pencil and pretended to review my answers and acted like I was going to go forward to turn in the answer sheet. This dude then gets up, and turns in his answer sheet. I then quickly corrected my own answers and turned in my sheet.
The next time we met in class, he had an F and I had a B. He was pissed! He didn't understand what had happened at all!

A week later, a bunch of us were taking a break in the computer lab. The same dude comes in and starts complaining how he got arrested the night before. He said that he was drunk and used a black powder pistol to shoot out the front window of a store in his neighborhood. He was a class act all the way! After that, he dropped out, we never saw him again.