This happened to me in undergrad with an autograded class. I remember soloing the class and thinking that the assignments were super hard. They would post grade averages for assignments and I was doing worse than usual. I remember a TA posting about cheating being an issue. They even released a graph of anonymized student repositories with edges indicating a detected instance of cheating Turned out that a HUGE cohort…
The students hunting for "the snitch" adds another layer of dysfunction. If someone joins the group chat and leaves because they notice other people cheating, then they could become targets of the other students. That's not the sort of college experience anyone wants to have.