Another reporting of the incident (http://www.insidehighered.com/news/2013/02/12/students-boycott-final-challenge-professors-grading-policy-and-get#ixzz2KnL9ysq

Another reporting of the incident (http://www.insidehighered.com/news/2013/02/12/students-boycott-final-challenge-professors-grading-policy-and-get#ixzz2KnL9ysqU http://www.insidehighered.com/news/2013/02/12/students-boyco...) actually explains some of the student logic: Andrew Kelly, a student in Fröhlich’s Introduction to Programming class who was one of the boycott’s key organizers, explained the logic of the students' decision via e-mail: "Handing out 0's to your classmates will not improve your performance in this course," Kelly said. This is actually not an interesting problem from the game theory perspective: defection gains you nothing. That is, if you're the only person who defects, your situation is the same if no one had defected. I'm assuming here that the grade curving is local to the assignments. Handing out zeroes to your classmates will help if your overall number of points goes up, and overall number of points in the class determines final grade.