This was first posted to YouTube last summer, but has gone viral in the last 24 hours after someone posted it to Reddit. The Reddit post says it's set in Wildwood, New Jersey, and begins as police are writing a guy a ticket for wearing a t-shirt with profanity. I can't find a news account of the incident to verify that.
What is clear is that the officers are harassing a man who is legally recording the incident from a distance that in no way physically interferes with what the police are doing. One officer threatens to destroy his camera if he doesn't put it away. Toward the end, several more officers confront the man again. One of them then tells him he'll be "locked up" for disobeying an order unless he stops recording.
I've sent an email to the user who posted the video and left a message with the Wildwood police department to see what has happened since.