Tufts University has sent out a letter that is sure to spook Greek life students ahead of Halloween weekend. Students involved in fraternities and sororities at the Massachusetts school are being told to not wear anything that could offend others during Halloween celebrations – or risk getting investigated by campus police and being slapped with “serious disciplinary sanctions.”

The order came in a note written by the leaders of the four Greek life councils on campus. It contained few specifics. “The costumes that people choose to wear have an effect on everyone around them whether they realize it or not,” the letter says. It goes on to state that “outfits relating to tragedy, controversy, or acts of violence are also inappropriate. We need to set a precedent that people’s customs cannot and will not be our costumes.” FULL REPORT