You shouldn't like messing with your students.
One of James' students consistently disrupted his classes with talking and pranks.
James wants his student to stop disrupting the class.
James tells the student he can play on his phone as long as he's silent.
James deliberately asked his problem student to solve impossible problems on the board in front of everyone.
The problem student still doesn't learn anything, but at least isn't distracting the other students.
James' student fell silent and started crying in class, prompting the student's parents to call the principal to complain.