The Truth About Cars  carries this story of a pair of local police officers beating up an old man on a bogus-sounding speeding charge, but there's more info in the source decision, a PDF. 

After being pulled over, Miller said that he got out of his truck and asked the officers what the problem was. He said that he told the officers that when he sees the 55-mile- per-hour sign in plain sight he begins picking up his speed and that the officer responded that he “lacked about 100 feet,” meaning that he was one hundred feet premature in speeding up his vehicle. Next, Miller stated that the officer told him to produce his license and insurance certificate. Miller testified:

I told him I didn’t believe. I said I wasn’t speeding, and uh, his next words were-everything was fine until then-his next words were, Officer Hatchett said I can see right now you’re going to need an attitude adjustment. And that’s when he made me mad.

Q. Then what happened?

A. Well, after some talking–I did punch my right fist in my left hand, but I never was aggressive to either officer. I know better than that. But it did make me mad. ... And, uh, and then I told him [I] was going to go home–go get in my truck and go home, and I turned my back on them and that’s when they bound me on the concrete and I told them they were hurting me. And one of them then pushed my head down into the alert line and busted my head, and, uh, then they put the handcuffs on me.

TTAC's take is that the police used excessive force, and the court agreed, but being rude right back to police is never a great idea. Not to mention being uncooperative:

Miller admitted refusing to produce his driver’s license, registration, and proof of insurance. He further admitted telling the officers “It’s not happening today.” He admitted that he intended to leave the traffic stop because of the way he was treated by the officers. Miller stated that he made no aggressive moves toward the officers, but he admitted that he did not have any respect for the officers, whom he referred to as “smart-alecks.”

Miller’s wife, Janet, testified that when she went to pick her husband up at the police station she inquired of the two officers what had happened and thatOfficer Hatchett responded that Miller had turned his back and “You don’t turn your back on a cop.”

It doesn't reflect well on either police restraint or individual rights, but unfortunately it sounds like eminently practical advice.