Be careful what you store on your smartphone if you plan to drive in Michigan.

Since at least 2008, State Police in Michigan have been operating under a policy that lets them extract and search all the data on your cell phone without a warrant, without your consent and without any reason to believe you might have done anything wrong.

They extract the data using one of five mobile computer-forensic devices the agency bought from CelleBrite that can bypass your own security and snag all your pictures, text messages, email and documents and even GPS data.

There is no defined policy or statement from the Michigan State Police online announcing or explaining the practice.

In fact, the Michigan branch of the American Civil Liberties Union (ACLU) had to file a Freedom of Information Act (FOIA) request in 2008 to get any records or documentation at all.

It got documentation proving the Michigan State Police had five of the CelleBrite devices, but no indication of how or how often they were being used.

"There is great potential for abuse here by a police officer or a state trooper who may not be monitored or supervised on the street," according to Mark Fancher, an attorney for the ACLU.

Getting detailed records, the MSP claimed, would cost $544,680 to pay for the time and effort of retrieving the data and assembling the documentation describing what the State Police were doing with the cell phone data extractors.

IT asked the ACLU to pay $272,340 as a deposit on that cost before giving up a single document.

To reduce the cost, the ACLU narrowed its request to cover smaller periods of time, rather than asking for all documents related to the seizures.

Each time the Michigan State Police told it that no documents existed for whatever time period the ACLU was asking about and refused to say when the devices had been used and what time period documents might exist covering them, according to the ACLU's version of events.

The Michigan ACLU wrote a letter April 13 to the director of the Michigan State Police complaining the practice violates Fourth Amendment rules against illegal search and seizure.

"The Fourth Amendment protects citizens from unreasonable searches," the letter read, in part

The Michigan State Police have made no public statements giving its end of the story.

The practice is similar to one followed by the Department of Homeland Security, which has decided it is allowed to search, copy or confiscate laptops, cell phones and other electronic devices from people crossing the U.S. border legally, even without any suspicion of wrongdoing.

The national ACLU and several lawyers' associations are suing to overturn that practice on the grounds it violates both First and Fourth Amendment rights of the 6,500 people whose data had been cloned or confiscated as of June of 2010.

Both DHS and the Michigan State Police, btw, are public agencies, subject to the laws of the United States, no matter how strongly members of them believe they belong to fiefdoms that can create their own laws and trample the rights of others with impunity.

They should be allowed to do their jobs, chase the bad guys and even eavesdrop on or confiscate digital data -- within rules specifically designed to keep police and other agencies from running amok pursuing their investigations too eagerly.

Whether those rules apply to a particular situation or technology is not up to the police agency applying them. It is up to courts who are responsible for drawing the line between appropriately aggressive investigation and police-state tactics based on the principle that everyone is guilty of something and police are within their rights to lie, cheat or steal to get evidence proving it.

Rules against overly aggressive policing exist for a reason. Law enforcement is difficult, dangerous, frustrating work. People who do it are often noble, brave and self-sacrificing.

They're still people, with all the weaknesses the rest of us enjoy, including the temptation to forget about a rule or two when the result is a good one, or would make it much easier for us to do the job we're going to have to do anyway.

It's easy to justify in your own mind, even if it doesn't work out in every specific situation.

When cops do that, the result is often a lot more serious than when you do, just as your big mistake might inconvenience some people, but similar ones by surgeons, airline pilots or bus drivers could kill them.

Having all the data sucked from your cell phone during a routine traffic stop isn't going to kill you; probably.

It does break down an important barrier between the convenience citizens should give up to help keep the peace, and restrictions on the authority of police that keep a peaceful state from becoming a police state.

This story, "Mich. State Police confiscate cell data at traffic stops; won't say when or why" was originally published by ITworld .