Wiretaps are governed by Part VI of the Criminal Code.
There are four categories of wiretap:
- a general wiretap authorized under s. 185 and 186.
- a wiretap with consent under s. 184.2
- an emergency wiretap under s. 184.1, 184.4 and 188
- video intercepts s. 487.01
The emergency wiretap (s. 184.1), exceptional circumstances wiretaps (s. 184.4), and video intercepts (s. 487.01) do not require full judicial authorization.
A wilful interception of "a private communication" without authorization is a indictable offence under s. 184 with a maximum penalty of 5 years. This offence does not include situations where one of the parties consents (s.184(2)).
An interception of a private communication under a Part VI authorization is a search and seizure under s. 8 of the Charter.
The right to full answer and defence permits the accused to examine an edited version of the materials available to the authorizing judge to support the wiretap authorization.
Modern electronic surveillance has been singled out as a particularly powerful form of privacy intrusion. But unregulated, it would destroy any sort of privacy and would threaten society.
- R v Grant 1999 CanLII 3694 (ON CA), (1999), 132 CCC (3d) 531 (S.C.C.) at 539
- R v Garofoli, 1990 CanLII 52 (SCC),  2 SCR 1421 at para 1433, 1452
R v Duarte,  1 SCR 30, 1990 CanLII 150 (SCC) - LaForest J referring to electronic surveillance as "superbly" equipped to fight crime, but left unregulated would mean "privacy no longer had any meaning"
R v Wong,  3 SCR 36, 1990 CanLII 56 (SCC) - LaForest J suggesting that electronic surveillance would "annihilate privacy"
R v Wise,  1 SCR 527, 1992 CanLII 125 (SCC) - LaForest J (dissenting) suggesting that surviellance was a "danger to individual autonomy and the organization of a free society”)
The modern legislation protecting against the interception of private communications arose from the 1969 Ouimet report which resulted in the Protection of Privacy Act.
R. Ouimet, Report of the Canadian Committee on Corrections, Towards Unity: Criminal Justice and Corrections (Ottawa: Information Canada, 1969) cited in detail at R v Nguyen, 2001 ABPC 52 (CanLII) at para 17
R v Lyons (1984), 15 CCC (3d0 417 at p.453, 1984 CanLII 30 (SCC),  2 SCR 633 - comments on the origin of the wiretap provisions
The purpose of these provisions is to "strike a balance between the protection of privacy and the availability of effective law enforcement techniques". 
Electronic surveillance has the potential to "annihilate" any expectation of privacy in our communications. Society should not expose us to permanent electronic surveillance.
Surveillance is one of the "the greatest leveler[s] of human privacy ever known".
Nguyen at para 17
Regina v Welsh and Iannuzzi (No. 6), 1977 CanLII 1215 (ON CA), (1977) 32 CCC (2d) 363 at p. 369
R v Duarte, 1990 CanLII 150 (SCC),  1 SCR 30, (1990), 53 CCC (3d) 1 (SCC) at p. 11 (CCC)
see also United States v White, 201 US 745 (1971) at p.756 ("electronic surveillance is the greatest leveler of human privacy ever known")
- United States v White, 201 U.S. 745 (1971) at p. 756
Under s.183, a "private communication" refers to any "oral communication or any telecommunication, that is made by an originator thereof who is in Canada or is intended by the originator to be received by a person who is in Canada and that is made under circumstances where the originator expects that it will not be intercepted by any other person other than the person intended by the originator to receive it".
A communication is private where the originator has a reasonable expectation that the communication would "not be intercepted by any person other than the person intended by the originator to receive it". The intention of who is to receive the communication includes those who the originator had knowledge would receive it but may not desire them to receive it.
Where it is reasonable to expect that the communication may be listened to or recorded, then it is not a private communication.
Communication requires some exchange of information between persons and not simply all information capturable by the interception.  Consequently, sounds not intended to convey information does not constitute a communication.
The following has been found not to be a "private communication":
- Electronic signals captured by a digital number recorder (DNR) 
- communication of a paging device.
- a prayer to God as God does not meet the legal definition of a person.
- a cassette sent through the mail
- prayers to God
The "originator" refers to the person whose "remarks which the Crown seeks to adduce in evidence" and are protected under Part VI of the Code.
R c Kyling, 2009 QCCS 3311 (CanLII)
- R v Goldman, 1979 CanLII 60 (SCC),  1 SCR 976
R v Newall, 1982 CanLII 276 (BC SC)
R v Davie, 1980 CanLII 323 (BC CA)
- R v Balatoni, 2003 CanLII 13174 (ON SC) at para 8
R v Fegan, 1993 CanLII 8607 (ON CA), (1993), 80 CCC (3d) 356
c.f. R v Griffith (1989) 44 CCC (3d) 63 (Ont. Dis. Ct.)(*no link)
R v Lubovac (1990) 52 CCC (3d) 551 (ABCA)(*no link)
- R v Davie
- R v Newall, 1982 CanLII 276 (BC SC)
- R v Davie
- R v Goldman, 1979 CanLII 60 (SCC),  1 SCR 976
"Interception" means to "listen to, record or acquire a communication or acquire the substance, meaning or purport thereof;"(s. 183).
The interception must be done by way of an "electromagnetic, acoustic, mechanical or other device" (s.183).
Consequently, simply to use one's human senses without technological aids does not invoke Part VI. 
Telephone communications between the accused and the police who answers the phone at a drug house and assumes the identity of the home owner is not covered by Part VI.
There does not need to be temporal connection between the message seizure and the transmission of the message.
R v Beckner (1978), 43 CCC (2d) 356(*no link) -- officer overhears conversation between accused and a friend
R v Kopinsky, 1985 CanLII 1191 (AB QB)
R v Singh, 1998 CanLII 4819 (BC CA)
R v McQueen (1979) 25 CCC (2d) 262 (SKQB)(*no link) (“The [wiretap provisions are] aimed at preventing a third party from intercepting the private communication between two people. It is not intended to apply to the case where there are only two persons involved and one receives a message by impersonation of fraud.”)
see also R v Giles, 2007 BCSC 1147 (CanLII), at para 31
- R v Telus Communications, 2013 SCC 16 (CanLII) per plurality reasons at para 35 ("definition of “intercept” that the interception of a private communication be simultaneous or contemporaneous with the making of the communication itself")
Section 35 of the Interpretation Act defines "telecommunications" as: "means the emission, transmission or reception of signs, signals, writing, images, sounds or intelligence of any nature by any wire, cable, radio, optical or other electromagnetic system, or by any similar technical system"
This definition was found to include technology such as Dialed number recorders.
This term is also used in the offence of Child Luring (Offence), Agree or Arrange a Sexual Offence Against Child (Offence), and Telecommunication Offences (Offence).
Within the provisions of the wiretap sections of the code, "offence" refers to a specific closed-list of offences. Those offences are listed within s. 2. It will include any conspiracies, attempts or counselling to commit the offence, or any accessories after the fact.
- See Criminal Code and Related Definitions
- see s. 183 definition of "offence"
- Intercept of Private Communications (Offence)
- Third Party Wiretaps
- Consent Wiretaps
- Warrantless Wiretaps
- Admitting Wiretap Evidence
- Sealing and Unsealing Warrants