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IL has no such "employee fiduciary responsibility law" as employment in IL is at will unless there are written contracts to the contrary. So now you have a contract, he is in breach of the contract by violating both the non-compete and non-solicitation clauses. He would be liable to you for damages for breaching the contract and those damages would not only include your lost profits, but also the attorney's fees and costs for having to sue him for breaching the contract. Thus, it truly is worth suing him over this breach of contract and seeking not only monetary damages, but also seeking a injunction against him which would be a court order prohibiting him from taking any more customers or from continuing to violate the non-compete agreement.
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