Here's the legal analysis, as presented by the ACLU of Minnesota:

In its brief, ACLU-MN argued that in Minnesota petty misdemeanor prosecutions, the prosecutor has the burden of proof to show that an individual is guilty beyond a reasonable doubt; however, the Minneapolis ordinance relieves the prosecutor from the burden to prove that the owner was actually the driver of the vehicle that was photographed going through the red light.

In addition, State law prohibits local traffic regulations from being in conflict with state law. The Minneapolis ordinance conflicts with state law because it shifts liability for traffic light violations from the driver to the owner. During the 2001 and 2003 Legislative Sessions, the Minnesota Legislature considered and rejected bills that would have allowed local governments to use automated cameras to enforce traffic regulations.

The broader privacy implications of having the government photograph our every public (or quasi-public) move is discussed in this neat article from Minnesota Public Radio. Here's an example of a Photo Cop photo, also courtesy of MPR.

Minneapolis now has a bunch of expensive cameras -- it apparently paid a half a million or so -- and no revenue stream from Photo Cop-issued citations to pay for them. Not to mention the headache of sorting through all the people who have pending Photo Cop tickets.

More than 7,000 people whose tickets are pending will be sent a letter informing them to hold off on payment until the city makes its next step, said Chief District Judge Lucy Wieland. Another 3,000 people whose licenses were suspended because of a Stop on Red ticket will regain driving privileges. It wasn't clear Tuesday what the process would be for returning licenses.

Maybe Minneapolis should have thought of this before deciding to ignore the law.