I don't like cheaters. Cheating is dishonest. Not only that, but cheating actually hurts people in the long run -- think about it, they graduate with a degree that they didn't really earn. And how much is a degree worth if you haven't really earned it? (Hint: Not very much.)
I don't feel like writing all the dirty details, but here are the basics: someone got ahold of the answer sheet and shared it with classmates. The professor and dean figured it out, due partially to someone who tipped them off anonymously. They have a way to figure out who cheated, and the cheaters will be dealt with...unless they confess that they cheated, in which case they are off the hook.
Personally, I think they're being too nice. Personally, I think everyone who cheated ought to face repercussions.
Also, everyone will have to take a new exam in place of the one already taken.
I do like that, but if I were one of the students in the class I would be very angry as heck with my classmates who cheated and made it necessary for me to retake an exam.
Interestingly, someone recorded the professor confronting the class about it, and the Pirate shared it in his post. I watched it, and it is quite impressive. It's fifteen minutes long, so you might not want to watch it due to its length, but if you're interested here it is.
If you want to find out more, you can read the Pirate's post about it here.