No person shall retaliate against, coerce, intimidate, threaten, or interfere with any other person who:
(1) has opposed any act or practice of the person that is collusive or in restraint of trade;
(2) has lodged a complaint or has testified, assisted, or participated in any manner with the Attorney General or a State’s Attorney in an investigation of acts or practices that are collusive or in restraint of trade;
(3) is known by the person to be about to lodge a complaint or testify, assist, or participate in any manner in an investigation of acts or practices that are collusive or in restraint of trade; or
(4) is believed by the person to have acted as described in subdivision (1), (2), or (3) of this subsection.