I've personally run into a situation like that. I've had random people that I've encountered from another school tell me what my sorority was like on their campus and joke or poke fun. I simply ignore their statements and just remind them that each chapter will be different.
Personally I like to keep in mind something one of my theatre directors once said... you're only as strong as your weakest character. I believe that whole heartidly. So I hope that helps to put things into perspective.
If it were a friend that was making the comments I might suggest reminding them how much your organization means to you and you'd rather not hear them bad mouth it...regardless.
Hootie
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What do you get when you cross an Alpha Omicron Pi and a Sigma Phi Epsilon? A beautiful Chi Omega!!!
Zeta Delta Chapter of Chi Omega
http://www.unomaha.edu/~comega