Most states have statutes setting forth what constitutes false advertising or theft of a business opportunity. You need to review statutes in your state to see what the specific elements are for false advertising or theft of a business opportunity.From what you have stated in your question, if your former employee is posting information to the general public on his company website that he actually built homes that your company built through his new company, then he seems to be advertising falsely.A false advertisement violation is essentially placing misleading or false information in one's advertising.Theft of a business opportunity is something else. It occurs when someone uses improper conduct to interfere with an existing business relationship between two people where the relationship ends with the purpose that one of the people in the business relationship will now do businses with the person who used the improper conduct to end the prior business relationship.