Gee thanks. Which flag would that be? CBF? First National? Second National? Naval Jack? State flag?
People that tell other people what they can and cannot fly when and where remind me too much of busybodies that have nothing better to do than interfere with others' natural rights (i.e. yankees).
People have every right to fly whatever non-American flag they want, whether it's the Mexican flag or the Secessionist flag. That doesn't mean that others can't draw their own conclusions about it.