This happened after I had got out of high school and I was living in Orange County California which is a part of the metro Los Angeles Area.
Back in those days when you hitchhiked around LA the police would routinely stop you, demand ID, and run you thru the computer to see if you had any warrants out for your arrest.
In this case I was hitchhiking on Broadway Road just west of Harbor Blvd in Anaheim and an Anaheim Police Officer stopped me to shake me down.
I had an American flag sown on the back of my Levis and the Anaheim Police officer ripped it off my pants and threatened to arrest me for being disrespectful toward the flags. Yes sure we have free speech in America. You can say anything you want that the police agree with.
This happened during the Vietnam War and a lot of the police hated people like me who though the war was wrong. I guess there still are a lot of police who hate people who think the war is wrong. Except now they hate people who think the Iraq war is wrong.