The justices declined to review a lower court ruling that found the state's “anti-eavesdropping law” to be in violation of a person’s free speech rights when used against anyone who records police officers.

By refusing to review the case, the high court leaves the ban on the law in place.

The law set out a maximum prison term of 15 years.

In 2010 the American Civil Liberties Union (ACLU) filed a lawsuit to block prosecution of ACLU staff for recording police officers performing their duties in public places.

Harvey Grossman, legal director of the ACLU of Illinois, said the organization "continues to believe that in order to make the rights of free expression and petition effective, individuals and organizations must be able to freely gather and record information about the conduct of government and their agents – especially the police."