Breach of Confidence
In order to establish an actionable breach of confidence, the complainant must prove (a) that the information conveyed was confidential, (b) that it was communicated in confidence, (c) that it was misused by the party to whom it was communicated, and (d) detriment to the complainant. International Corona v Lac Minerals,  2 S.C.R. 574.
A person who receives confidential information in circumstances of confidence has a duty not to use that information for any purpose other than that for which it was conveyed. If the information is used for such an unauthorized purpose, and the person who provided that confidential information suffers a detriment, the court will grant a remedy.
"In establishing a breach of a duty of confidence, the relevant question to be asked is, "what is the confidee entitled to do with the information?" and not, "to what use he is prohibited from putting it?" Any use other than a permitted use is prohibited and amounts to a breach of duty. When information is provided in confidence, the obligation is on the confidee to show that the use to which he put the information is not a prohibited use." International Corona v Lac Minerals,  2 S.C.R. 574.
In certain circumstances, the recipient of confidential information will provide it to third parties. Where such third parties are in possession of confidential information, a key consideration for the court will be whether the third party knew or ought to have known that the information is confidential. This may be implied from the nature of the information itself or the circumstances in which the third party received it.
Roger D. McConchie has considerable experience advising clients with respect to breach of confidence claims.