Is chess all about violence?
Actually, it's not aggressive, but just more competitive. Sport games, if not played on keyboards or game pads but "active" controllers like Kinect, TrackIR etc, can sometimes turn out into a lightweight excercise. I played tons of classic DOS sport games (mostly soccer and tennis), they were not aggressive - just like table soccer or ping pong. People on Common Sense Media may be very hilarious - they may even think that chess encourages kids to be more evil, while draughts (checkers) are MORE violent than chess!!!