Wis. Stat. § 134.72: Prohibition of certain unsolicited messages by facsimile machine.

(1) Definitions. In this section:

(a) “Facsimile machine” means a machine that transmits copies of documents by means of a telephone line, telegraph line, microwave, satellite, radio wave, fiber optics, coaxial cable or any other transmission facility or any switching device.

(b) “Facsimile solicitation” means the unsolicited transmission of a document by a facsimile machine for the purpose of encouraging a person to purchase property, goods or services.

(2) Prohibitions.

(a) A person may not make a facsimile solicitation without the consent of the person solicited unless all of the following apply:

1. The document transmitted by facsimile machine does not exceed one page in length and is received by the person solicited after 9 p.m. and before 6 a.m.

2. The person making the facsimile solicitation has had a previous business relationship with the person solicited.

3. The document transmitted by facsimile machine contains the name of the person transmitting the document.

(b) Notwithstanding par. (a), a person may not make a facsimile solicitation to a person who has notified the facsimile solicitor in writing, by telephone, or by facsimile transmission that the person does not want to receive facsimile solicitation.

(c) A facsimile solicitor who receives notice under par. (b) may not disclose to another the facsimile transmission number of the person who gave the notice under par. (b). Each disclosure of a facsimile transmission number is a separate violation of this paragraph.

(3) Territorial application.

(a) Intrastate. This section applies to any intrastate facsimile solicitation.

(b) Interstate. This section applies to any interstate facsimile solicitation received by a person in this state.

(4) Penalty. A person who violates this section may be required to forfeit not more than $500.