Mich. Comp. Laws § 450.109

Sec. 109. Same; persons liable for damage for encouraging breach of contracts and agreements. Any person, firm, or corporation who solicits or persuades or permits or aids or abets, any stockholder and/or member or other person to breach a contract with a cooperative corporation, by accepting or receiving from such stockholder and/or member or other person, products for sale, marketing, manufacturing, or processing for sale, contrary to the terms of any marketing agreement of which said person or any member of said firm or any officer or manager of said corporation has knowledge or notice, shall be liable to the cooperative corporation aggrieved in a civil suit in the penal sum of $500.00 for each such contract; and such cooperative corporation shall be entitled to an injunction against such person, firm, or corporation to prevent further breaches and a multiplicity of actions thereon. In addition, said person, firm, or corporation shall pay to the cooperative a reasonable attorney's fee and all costs involved in any litigation or proceedings at law or chancery.