I don't know if it was hazing or not, but the specific activity Kappa got in trouble for was a Boulder Run. Boulder Runs are a DePauw tradition where students run from their greek house/dorm to the boulder and back naked the night of the first snow of winter. However, boulder runs are quite common at any point during the school year and not just the first snow of the season. The boulder is is in the north central part of campus and the run from Kappa to the Boulder is more than enough time to get...noticed. Boulder Runs are not exclusive to Kappa; just about every house and every dorm does boulder runs on a regular basis.
This is the boulder:
http://www.depauw.edu/visitors/traditions/boulder.asp