The First Amendment protects ugly speech.

http://www.thebeerbarrel.net/showthread.php?8006-The-Right-To-Be-a-Jerk

If you watch the clip, you might come away with the impression that Cox acted like an obnoxious punk. How? He said something that wasn't nice to a policeman, and he said it loudly. And as Kelley testified, "his attitude and the way he went about carrying himself" were on the sassy side—though there's no law requiring citizens to display cringing submission in the presence of a policeman, either.

Now, none of us is a mind reader. But it seems fair to wonder whether Kelley would have written Cox up if Cox had bellowed something more flattering to the ego, such as: "Thanks for keeping our streets safe, Officer!"