How do i insult a police officer legally?

i really really really hate police. i just want to go up to a police officer and beat the crap out of him or spit in his face/coffee. all they do is get in everyone's way , includiing mine and prevent us from having fun . I HATE THE POLICE! what is a good way to insult one that wont let me end up in jail, i supposedly have free speech but flippin the bird can get me done over for disorderly conduct.