About 5 years ago, I had 3 students who worked as a team to cheat.
* The ringleader placed his iPhone under his leg.
* He would lean back in his chair and hold the exam sheets up in the air. It looked a little unusual, but it (initially) seemed innocuous.
* What he was really doing was pointing the sheets downward toward the camera peeking out from under his leg.
* He was broadcasting the exam to God-knows-where.
* He and the other two students then received answers via tiny earpieces.
* In addition, the two other students would call me over to "ask clarification questions." In reality, they were trying to distract me while the ringleader broadcast the exam.
* I eventually realized they were cheating (after exam 1), but I couldn't figure out how, until another student (exam 2) approached me with a note that read, "The guy to my right has his phone under his leg. Every time you circle the room, he pushes it completely under his leg so you can't see it."
* At that point, however, each student was taking a slightly different exam (unbeknownst to them).
The ringleader emailed me at the end of the semester and said something to the effect of: "I know I don't deserve to pass, but if you fail me, I will have to stay an extra semester."
I ended up failing all three.