Mustafa the Maths Mis-calculator
Mustafa and his classmates were given a piece of maths coursework to complete. They were not told to work in groups, but the class were all friends and were used to working together so they arranged to meet and go through the coursework together.
They agreed the calculations and answers together and submitted the same answers. Mustafa thought this would be fine because it was maths and so it was obvious that they would all be submitting the same answers regardless of whether or not they worked together. The tutor would never know. When Mustafa went to collect his results, he was given a letter inviting him to an academic misconduct panel to investigate possible academic misconduct. It turned out that when marking the work, the tutor noticed that all of the students had submitted papers with exactly the same mistakes in, and they had all used exactly the same calculations. This was more than just co-incidence, and the only explanation was that the students had not worked individually on the coursework, but had instead colluded with each other to get the work done.
The Academic Misconduct Panel agreed with the tutor and found Mustafa guilty of collusion. They failed his piece of work, but because it was his first submission and his first academic misconduct offence, they allowed him to re-sit the coursework with a capped mark of 40%.
Moral of the story
If you work with friends when you are not supposed to, the School will be able to tell.