This past Halloween a group of Penn State students dressed up as Virginia Tech shooting victims for a small party of six students.
The costume would have been only known to the small gathering, until one of the party goers posted the pictures on Facebook. There, it was discovered by a Virginia Tech student and a war of Facebook groups ensued.  A quick search on Facebook indicates that the groups are only viewable by student that attend the respective school.
To hear one of their explanations for the costume decision, check out the YouTube video on Mashable.