Optus Networks Pty Ltd v Telstra Corporation (2010) 265 ALR 281

Facts: Optus and Telstra owned huge proportions of telecommunications; Optus could offer services over the Telstra network, even though it was physically owned by Telstra (and vice versa). As an Optus customer, this allowed Telstra to work out usage patterns. Telstra promised Optus not to misuse the information to steal each other's customers. If they did it, damages will be paid at a set rate. Telstra breached the contract. Optus could sue and recover damages under the contract and sought to get an account of profits under the equitable breach of confidence (remedy based on Telstra’s gain). Optus argued they could take that money because of Telstra’s misuse of confidential information derived from the benefit of having that information. 

Held (Finn, Sundberg and Jacobson JJ at [39]): Established 4 elements in assessing whether Optus had established an equitable breach of confidence against Telstra:

1. The information must be identified with specificity;

2. It must have the necessary quality of confidence;

3. It must have been received by Telstra in circumstances importing an obligation of confidence; and

4. There must be an actual or threatened misuse of the information without Optus’s consent.