Let me begin by saying I believe in freedom of speech. It is a founding principle of this country, and for that reason, legally, I believe everyone should have the right to wave the stars and bars.
That being said, while I think it should remain legal, it is ethically abhorent. I can't wrap my mind aroud someone wanting to proudly wave the banner of a bunch of people who were so determined to keep other human beings as property that they turned traitor and declared themselves no longer Americans. The confederacy, for the entirety of its existance, was this country's enemy. You're flying the flag of your nation's enemy. What the hell is the matter with you?
"It's a symbol of the south's history and heritage." Well, yes, it is. That's not necessarily a good thing. You could say the same thing about the Swastika and Germany. Just because it's a part of your area's history doesn't mean it's a GOOD part of its history. It doesn't mean you should be PROUD of it just because it's part of your heritage.