That should come as no surprise, really. Giving a cop "the finger" as you drive down the isn't hurting anyone, so the cop has no right to stop you. But keep one of "Steakley's Golden Rules" in mind: just because something is Constitution to do, doesn't make doing it a good idea. Sure, the cop can't pull you over for the bird, but he can sure as heck follow you until he finds another reason to pull you over. Then you're all his.
Case in point, from right here in Marietta (Cobb County):
MARIETTA, Ga. - A Marietta woman says that she's filing a federal lawsuit against police after she was arrested for allegedly using profanity at officers. The woman says her First Amendment rights were violated by the arrest.
Amy Barnes, a member of the Occupy movement, says she flipped off police and cussed at them as she was on her bike on Austell Road near her Marietta home. Two Cobb Police officers had teenagers stopped outside a store as Barnes showed her displeasure from the moving bike.
Police followed and arrested her couple of blocks away.
"They told me I shouldn't be presenting a lewd gesture in front of children," said Barnes.
Police charged Barnes with disorderly conduct. She says she spent 23 hours in jail -- six in solitary confinement. The misdemeanor is still making its' way through the courts, but Barnes' attorney, Cynthia Counts, says police violated Barnes' constitutional rights.
Like I said, just because something is Constitutional to do, doesn't make doing it a good idea.
UPDATE: Amy Barnes won.