What can we do when a large group of people commit a crime?

It seems to me when a large group of people commit a crime it no longer becomes a crime.

In South Korea, medical students must take a national exam in order to finally get their degree. However, there were only a few chosen locations with a limited capacity where those students can take exams. So, it was necessary to schedule students on different dates to take the exam. However, these smart students who happened to take the exam before others made a webpage and shared their exam problems. Since it is not possible to make different problems every other exam dates, those who took the exam later could get always perfect score by studying the problems on the webpage. This process eventually became a tradition that students who took exam before others were obliged to put the problems they had on the webpage. When this was discovered, no one could be blamed and no one was divested of his M.D. because almost everyone was involved.

When one bank gives mortgage loan to whom does not have the capability to repay, it is something to blame. However, when every bank does it, it becomes something to rescue.

When one person kills another, he is called a murderer. When a group of people kills another group, they are protectors.

So, I say we should take advantage of other people in a group, shouldn’t we?.