MADISON, Wis. -

There are about 4.5 million drivers in Wisconsin, and more than half may not know their personal information is being sold by the state Department of Transportation.

There are laws but almost no oversight to how the Wisconsin DOT uses drivers' information.

In all, the state makes millions of dollars by selling drivers' information, WISC-TV reported.

Before a person becomes an official Wisconsin driver and gets his or her license, there's time to consider two decisions at the Department of Motor Vehicles.

One is whether that person wishes to be recorded as a potential organ donor.

But drivers are also asked to check a box if they wish to have their name and address "withheld from the list the department sells."

About 2.5 million Wisconsin drivers didn't check the box to withhold their information. By not doing so, those drivers allow the DOT to sell their information on a monthly basis.

Some may not have noticed the other inquiry.

"It was kind of small (on the form). I didn't really notice it at first," said Sierra Scott, a Madison resident.

But it's not just a person's name and addresses. The driver record file includes a person's name, address, date of birth, gender, driver's license number and driving status.

The entire driver record file containing information on 2.5 million drivers can be purchased for $250.

"We produce a CD containing the record file and then we send that. Those funds are sent to the registration fee trust," said Taqwanya Smith, director for the DMV's Bureau of Driver Services.

In 2010, the DOT made $22,250 selling driver record files.

"I think the cost is representative of the amount of effort it takes to produce the records," Smith said.

Smith, who administers state and federal laws at the Wisconsin Department of Transportation, said that anyone can buy the driver record file, getting access to information for the drivers who haven't opted out.

"Wisconsin is an open records state, and by that Wisconsin presumes that the public has a right to know about information contained within government records," Smith said.

Federal law defines who can get the information and how they can use it.

"The (Drivers Privacy Protection Act) authorizes us to disclose to anyone meeting that criteria," Smith said.

But no state or federal agency tracks who is buying drivers' information or what they use it for. If people check the right box, they get the information, with no questions asked and no follow up, WISC-TV reported.

"Our responsibility ends once a person or entity receives that driver record file," Smith said.

Smith confirmed that federal law does not allow for the release of personal identifiers for surveys, marketing or solicitations.

But when WISC-TV asked her if this could be happening, Smith replied, "It could. We don't know if it is."

In 2009, Mark Grebner, president of Practical Political Consulting in Michigan, said he set out to update his Wisconsin voter file.

But because Wisconsin's voter file doesn't include date of birth, Practical Political Consulting looked to the Wisconsin DOT.

"The voter lists we sell, the candidates want to know how old people are," Grebner said. "We filled out the form properly; we sent it in. They (the DOT) sent back the data. I think they knew what we're doing."