This (via Wikipedia) is a story from the militarized Prussia of 1906:
On October 16, 1906 Voigt was ready for his next caper. He had purchased parts of used captain’s uniforms from different shops and tested their effect on soldiers. He had resigned from the shoe factory ten days previously. He took the uniform out of baggage storage, put it on and went to the local army barracks, stopped four grenadiers and a sergeant on their way back to barracks and told them to come with him. Indoctrinated to obey officers without question, they followed. He dismissed the commanding sergeant to report to his superiors and later commandeered 6 more soldiers from a shooting range. Then he took a train to Köpenick east of Berlin, occupied the local city hall with his soldiers and told them to cover all exits. He told the local Police to “care for law and order” and to “prevent calls to Berlin for one hour” at the local Post Office. He had the treasurer von Wiltberg and mayor Georg Langerhans arrested, supposedly for suspicions of crooked bookkeeping, and confiscated 4002 marks and 37 pfennigs – with a receipt, of course (he signed it with his former jail director’s name). Then he commandeered two carriages and told the grenadiers to take the arrestants to the Neue Wache in Berlin for interrogation. He told the remaining guards stand in their places for half an hour and then left for the train station. Later he changed to civilian clothes and had disappeared.
And this (via the New York Times) is the story of the DEA’s America in 2008:
GERALD, Mo. — Like so many rural communities in the country’s middle, this tiny town had wrestled for years with the woes of methamphetamine. Then, several months ago, a federal agent showed up. Busts began. Houses were ransacked. People, in handcuffs on their front lawns, named names. To some, like Mayor Otis Schulte, who considers the county around Gerald, population 1,171, “a meth capital of the United States,” the drug scourge seemed to be fading at last. Those whose homes were searched, though, grumbled about a peculiar change in what they understood, from television mainly, to be the law. They said the agent, a man some had come to know as “Sergeant Bill,” boasted that he did not need search warrants to enter their homes because he worked for the federal government. But after a reporter for the local weekly newspaper made a few calls about that claim, Gerald’s anti-drug campaign abruptly unraveled after less than five months. Sergeant Bill, it turned out, was no federal agent, but Bill A. Jakob, an unemployed former trucking company owner, a former security guard, a former wedding-performing minister, a former small-town cop from 23 miles down the road. Mr. Jakob, 36, is now the subject of a criminal investigation by federal authorities, and is likely to face charges related to impersonating a law enforcement officer, his lawyer said.
Draw your own conclusions.