Justice Donald Alexander criticized U.S. Cellular, saying it violated federal privacy law.
The lawyer for the husband in the case used subpoenas to get the texts from the wife and another man and was suspended for six months.
The judge ordered the Maine Board of Overseers of the Bar to alert state and federal prosecutors about U.S. Cellular's practices. He says U.S. Cellular violated the federal Stored Communications Act.
A spokeswoman for U.S. Cellular Corp. said Thursday the Chicago-based company is looking into the matter.
The judge's order was signed Jan. 31 and was first reported by the Bangor Daily News.