Confidential Information in UK Law

I start with the broad general principle (which I do not intend in any way to be definitive) that a duty of confidence arises when confidential information comes to the knowledge of a person (the confidant) in circumstances where he has notice, or is held to have agreed, that the information is confidential, with the effect that it would be just in all the circumstances that he should be precluded from disclosing the information to others.

But it is well settled that a duty of confidence may arise in equity independently of such cases; and I have expressed the circumstances in which the duty arises in broad terms, not merely to embrace those cases where a third party receives information from a person who is under a duty of confidence in respect of it, knowing that it has been disclosed by that person to him in breach of his duty of confidence, but also to include certain situations, beloved of law teachers - where an obviously confidential document is wafted by an electric fan out of a window into a crowded street, or when an obviously confidential document, such as a private diary, is dropped in a public place, and is then picked up by a passer-by.

It is that the principle of confidentiality only applies to information to the extent that it is confidential. In particular, once it has entered what is usually called the public domain (which means no more than that the information in question is so generally accessible that, in all the circumstances, it cannot be regarded as confidential) then, as a general rule, the principle of confidentiality can have no application to it.

Insofar as a photograph does more than convey information and intrudes on privacy by enabling the viewer to focus on intimate personal detail, there will be a fresh intrusion of privacy when each additional viewer sees the photograph and even when one who has seen a previous publication of the photograph, is confronted by a fresh publication of it.

Now the law imposes a 'duty of confidence' whenever a person receives information he knows or ought to know is fairly and reasonably to be regarded as confidential. The continuing use of the phrase 'duty of confidence' and the description of the information as 'confidential' is not altogether comfortable. Information about an individual's private life would not, in ordinary usage, be called 'confidential'. The essence of the tort is better encapsulated now as misuse of private information.

Accordingly, in deciding what was the ambit of an individual's 'private life' in particular circumstances courts need to be on guard against using as a touchstone a test which brings into account considerations which should more properly be considered at the later stage of proportionality. Essentially the touchstone of private life is whether in respect of the disclosed facts the person in question had a reasonable expectation of privacy.

First there is information which, because of its trivial character or its easy accessibility from public sources of information, cannot be regarded by reasonable persons or by the law as confidential at all. ' The servant is at liberty to impart it during his service or afterwards to anyone he pleases, even his master's competitor.