This was a recent appellate court opinion as to Cook County’s ban on assault weapons.
"(CN) - An Illinois county’s ban on assault weapons survived a constitutional challenge in an Illinois appellate court. The ban’s broad language “serves the legitimate purpose of protecting the public,” the court ruled. Matthew Wilson and two other plaintiffs sued Cook County and its commissioners and sheriff, seeking to have the Blair Holt Assault Weapons Ban declared unconstitutional.
The 1st District Appellate Court in Chicago upheld the trial court's ruling that certain limitations on weapons and ammunition do not violate the Second Amendment. "Defendants admit that the ordinance is broadly drawn, and it is, but that does not make it impermissibly vague. While there may not be perfect clarity in wording, the broad language serves the legitimate purpose of protecting the public," Presiding Justice Murphy wrote. "The trial court reviewed and detailed the ordinance's specific list of weapons and detailed definitions of what constitutes an assault weapon, and these constituted objective criteria for enforcement," Murphy added."
The entire court decision is reported here: