A class action lawsuit was filed this week against the city of Chicago by an attorney claiming that arrests of drivers talking on their cell phones made by the city's police officers were illegal.

The lawsuit states that Chicago police officers have been arresting and ticketing thousands of drivers violating the city's cell phone ban, which was imposed almost two years ago. Drivers are typically fined $75 if caught talking on their cell phones or up to $200 if they are involved in an accident.

Attorney Blake Horwitz, who filed the lawsuit against the city, Mayor Richard Daley, and several police officers, issued a statement saying that the law prohibiting Chicago residents from using cell phones while driving hasn't been properly enacted.

Horwitz's firm specializes in police misconduct and has sued the city of Chicago more than 100 times.

The law, 625 ILCS 5/11207, actually requires the city to put up signs that tell drivers not to talk on their cell phones when they're behind the wheel. But there are no such signs posted across the city of Chicago, which makes the fines and the arrests illegal, Horwitz said.

Horwitz is demanding that the city of Chicago dismiss any outstanding tickets and refund almost $2 million in fines collected since 2005, according to a report in the Chicago Tribune. In the lawsuit, Horwitz claims that the city has collected millions of dollars from over 25,000 citations. He said it is a way for the city to bring in extra money because of an insufficient budget.