Lights

Right now I am supervising a computer lab. The lab has large windows with an abundance of natural light. Two students and myself were happily working in this environment until a third showed up and with out a second of hesitation flipped on the florescent lights. I get the feeling that if a student were to walk into a room and do the opposite (turn off the lights) there would be some kind of backlash for this behavior. Why the double standard?