720 ILCS 5/21-10

(a) A person commits criminal use of a motion picture exhibition facility, when he or she, where a motion picture is being exhibited, knowingly operates an audiovisual recording function of a device without the consent of the owner or lessee of that exhibition facility and of the licensor of the motion picture being exhibited.

(b) Sentence. Criminal use of a motion picture exhibition facility is a Class 4 felony.

(c) The owner or lessee of a facility where a motion picture is being exhibited, the authorized agent or employee of that owner or lessee, or the licensor of the motion picture being exhibited or his or her agent or employee, who alerts law enforcement authorities of an alleged violation of this Section is not liable in any civil action arising out of measures taken by that owner, lessee, licensor, agent, or employee in the course of subsequently detaining a person that the owner, lessee, licensor, agent, or employee, in good faith believed to have violated this Section while awaiting the arrival of law enforcement authorities, unless the plaintiff in such an action shows by clear and convincing evidence that such measures were manifestly unreasonable or the period of detention was unreasonably long.

(d) This Section does not prevent any lawfully authorized investigative, law enforcement, protective, or intelligence gathering employee or agent of the State or federal government from operating any audiovisual recording device in any facility where a motion picture is being exhibited as part of lawfully authorized investigative, protective, law enforcement, or intelligence gathering activities.

(e) This Section does not apply to a person who operates an audiovisual recording function of a device in a retail establishment solely to demonstrate the use of that device for sales and display purposes.

(f) Nothing in this Section prevents the prosecution for conduct that constitutes a violation of this Section under any other provision of law providing for a greater penalty.

(g) In this Section, "audiovisual recording function" means the capability of a device to record or transmit a motion picture or any part of a motion picture by means of any technology now known or later developed and "facility" does not include a personal residence.