Can somebody explain to me what is considered to be fair notice and whether a law is "vague"? I've read an article under the Principles of Fundamental Justice, and it said:

A law is unconstitutionally vague where it does not give a person fair notice of what to avoid and does not limit the discretion of law enforcement with clear and explicit legislative standards.

Also, in R. v. Levkovic:

In accordance with s. 7  of the Charter , in a criminal context, a statutory provision must afford citizens fair notice of the consequences of their conduct and it must limit the discretion of those charged with its enforcement.

Does this mean that law enforcement has to give us fair notice, or the laws themselves are sufficient? If the laws give fair notice, does that mean citizens must read the laws to get this "fair notice"?

The law of concern is the Security of Information Act, specifically misappropriation of Trade Secrets, where it is a civil offense in Canada. In order for them to prosecute under criminal laws, surely they must provide "fair notice"?

  • The evidence-gathering and search warrant are an entirely separate and different part of the legal realm. This principle has nothing to do with specific people being told a specific thing.
    – user4657
    Commented Dec 30, 2017 at 20:17

2 Answers 2


The "fair notice" provision is completely unrelated to search warrants. The principle of fair notice is generally applicable to laws. It is irrelevant to specific people in specific situations being told specific facts.

This provision places a requirement on the law itself, that it must be clear about what it requires of the person(s) subject to it, and defines as much as possible the requirements of law enforcement with regard to that law.

It prevents unreasonably broad or general laws being passed that introduce significant "grey zone" for the average person, who is unsure of whether their actions are criminal or legitimate, despite having a reasonable knowledge of the law. It further prevents law enforcement using such a law for arbitrary prosecution by explaining precisely what is and is not sufficient for that law to be applicable.

  • Okay so if we scratch he part about the search warrant and the order, then fair notice applies to the laws that a party would be prosecuted pursuant to right? Like is the fair notice a physical notice or just included in the law. I still don't get it... forget the search warrant part
    – user14142
    Commented Dec 30, 2017 at 21:08
  • 1
    The law itself is fair notice of what the law either forbids or requires.
    – user4657
    Commented Dec 30, 2017 at 21:37

Nowhere in your quotations is any restriction placed on prosecutors or police. A law, or other statutory provison, must make clear what is forbidden, and may not allow those enforcing it too much discretion; that is all that is said.

If you want to know what a law says then yes, you must read it, and possibly either study jurisprudence or ask for a lawyer's interpretation.

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