What you describe isn't a law but a statute you can either 'consent' to or not. Nobody on this planet has the 'Right' or the 'Authority' to tell anybody else what to do WITHOUT THEIR CONSENT...this is an incontestable FACT. We are governed by CONSENT and we are policed by CONSENT. It all comes down to the good old Maritime Admiralty Law, legalese talk and how what you believe to be straightforward English is anything but.
Take the Police for instance...they have no right whatsoever to ask for your name, details...in fact anything at all if you do not give them consent. But they will bully and cajole you into unwittingly consenting by giving up the information they demand. When they ask you...'Do you understand' they are entering a contract with you, if you say 'yes' you have unwittingly agreed to 'Stand Under' and abide by whatever they decide. Never, ever say yes but question them.
The Common Law or Law of the Land is what mankind has made...they are universal, unchangeable based entirely on Common Sense! They are applied by Courts, called Courts de Jure (of Justice) and are set before a jury of 12. What we have happening all over the world however is something completely different.
This action in Illinois is in fact a STATUTE. Statutes are the legislated rules of societes created by Parliaments and Congresses to suit themselves. Like Common Law mankind also makes them but in this instance a select, self serving group changes them in accordance with its own desires, wishes, wants, needs depending on the situation...hence this 'unlawful' statute regards filming.
Cases brought about through statutes appear at a court of commerce, not law.
To be honest I'll just turn this answer into a hub...