I think that you should emphasize to your parents what a great job they did raising you. Show them by your actions that you are responsible and intelligent. If their only information about greek life comes from the media, they are probably concerned about your health and safety. Let them know that you would never do anything that would compromise your safety or your education. Check out the greek life section of your college's website with your parents. This might alleviate some of their concerns. Good luck!