In Canada, the Copyright Act provides a monopoly right to owners of copyrighted works. This implies no person can use the work without authorization or consent from the copyright owner. However, certain exceptions in the Act govern circumstances where a work will not be held to have been infringed.

Principal Defences

Defendants can, where applicable, argue that copyright infringement could not have taken place, as:

Other defences may be available to the defendants, in cases where some features of copyrighted work exists, but does not constitute infringement. These include:

Public Interest

At common law, copyright may be overridden for public interest reasons, albeit in very rare circumstances.

In Lion Laboratories v Evans, the copyrighted information about malfunctioning breathalyser machines was reproduced. Such reproduction was held to be justified, despite the nature of material, being confidential and protected by copyright. Court agreed to the defence of public interest, raised by defendants on ground of investigations made regarding the accuracy of the equipment to avoid incorrect readings when used by the police on motorist. As Griffiths LJ noted in his judgment:

I can see no sensible reason why this defence should be limited to cases in which there has been wrongdoing on the part of the plaintiffs.... No doubt it is in such circumstances that the defence will usually arise, but it is not difficult to think of instances where, although there has been no wrongdoing on the part of the plaintiff, it may be vital in the public interest to publish a part of his confidential information.

In Beloff v Pressdram Ltd, the defence of public interest has been interwoven with fair dealing. The court observed fair dealing as a statutory defence limited to infringement of copyright. On the other hand, public interest acts as a defence outside, and independent of statutes, which is based on principles of common law.

The public interest defence is identical to that available in cases concerning breach of confidence, and is available when the necessity to publish more than just short extracts is required. It is distinct from the power arising from the inherent jurisdiction of the courts "to refuse to allow their process to be used [to] give effect to contracts which are ... illegal, immoral or prejudicial to family life because they offend against the policy of the law."

Fair Dealing

The Copyright Act states that fair dealing exists when it is done:

In Hubbard v Vosper, Lord Denning MR observed, "It is impossible to define what is 'fair dealing.' It must be a question of degree," and "after all is said and done, it must be a matter of impression." He gave several guidelines for analyzing what is fair or not:

Hubbard was adopted in Canadian jurisprudence in 1997 in Allen v Toronto Star Newspapers Ltd, which ousted the 1943 Exchequer Court of Canada case of Zamacois v Douville and Marchand in the area of what constitutes fair dealing in illustrating a current news story. In so holding, Sedgwick J observed:

To the extent that this decision is considered an authority for the proposition that reproduction of an entire newspaper article or, in this case, a photograph of a magazine cover, can never be considered a fair dealing with the article (or magazine cover) for purposes of news summary or reporting, we respectfully disagree.

CCH Canadian Ltd v Law Society of Upper Canada, expanded upon that, with the Supreme Court of Canada holding that fair dealing, as well as related exceptions, is a user’s right. In order to maintain the proper balance between the rights of copyright owners and user’s interest, it must not be interpreted restrictively. It is also integral to the Act, and the defence is always available. The Court gave a two-stage test for determining whether fair dealing applies:

The effect of CCH has been for Canada becoming less rigid than the UK in interpreting fair dealing, and more flexible than the US approach of fair use in its copyright law. Further expansion of the jurisprudence came in 2012 with SOCAN v Bell Canada and Alberta (Education) v Canadian Copyright Licensing Agency (Access Copyright).

Regarding other specific matters concerning fair dealing:

Other statutory exceptions

Sections 29.21–32.3 provide other exceptions from copyright infringement in cases concerning:

Possible defences

Several other arguments have been presented as possible defences for copyright infringement: