03/27/2013 03:42 EDT | Updated 05/27/2013 05:12 EDT

What powers do police have for online surveillance?

Police need to have a special wiretap warrant to access a suspect's daily batch of text messages from their wireless provider, the Supreme Court of Canada decided Wednesday, in its latest ruling on privacy protection in the age of cellphones and digital communication.

The ruling recognized that text messages are a type of private electronic communication, so police need to meet a higher standard when seeking a judge's permission to access them than simply asking for a routine search warrant.

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The case worked its way up to Canada's top court as wireless provider Telus Corp., which opts to keep a database of text messages within its network for 30 days, argued it should not have to hand over clients' text messaging logs daily when police ask for them using a general search warrant.

Telus based its case on the argument that seizing the messages would be an "interception," which would require a wiretap warrant.

Wiretap warrants are more difficult for police to obtain than general search warrants because private communications are afforded special privacy provisions in the Criminal Code.

The decision affirms that there is no practical difference between texting and a traditional phone conversation, which would also require a wiretap warrant to be intercepted.

Special interception warrants

Canadian law allows the police to legally intercept Canadians' private communications without their knowledge or consent only through an intercept authorization warrant, said Abby Deshman, the director of the Canadian Civil Liberties Association public safety program.

Typically, police can apply for three types of warrants: a standard search warrant (which can include searching a computer and printing out data), a production order (which compels someone to hand over information stored in a physical space or on an electronic device) or a general warrant (which can be a little more wide-ranging).

But if police want to intercept a private communication they must apply for a wiretap authorization and meet a higher standard, including:

- having tried other investigative procedures;

- demonstrating that other investigative procedures have failed or are likely to fail;

- showing the urgency of the case makes it impractical to use only other investigative procedures.

If granted, interceptions are time-limited, and the person whose communication was intercepted will eventually be notified.

The CCLA was pleased with the court's decision and released a statement saying, "police may not use technical differences in how text messages are transmitted from one person to another to avoid the more rigorous scrutiny of a wiretap authorization."

However, there are situations when police do not require a warrant.

"The most concrete example is you don’t need to get a warrant to go into a private house if someone is screaming for help inside," said Deshman, adding there are many such circumstances when police do not need a warrant.

"The police can always ask for information. The question is, when can companies give that information over and what power do police have to receive it?"

Wiretapping in emergencies

In February, federal Justice Minister Rob Nicholson introduced a new bill, C-55, which would give police the right to intercept private communications without a warrant in emergency situations, like immediate harm to an individual or national security.

- RELATED: Government killing online surveillance bill

On the same day, the federal government killed the so-called Protecting Children from Internet Predators Act, or Bill C-30, after intense public lobbying over privacy concerns. Bill C-30 was heavily opposed for its "Big Brother" qualities.

Internet service providers would have been required to help police intercept and track online communications without a warrant.

Password protected phones

Police powers were also expanded last month when the Court of Appeal for Ontario ruled that officers have the right to search a person's phone — as long as it is not password protected.

If someone is arrested and that person's cellphone does not require a password to access text messages, photos, browsing history or call logs then police are allowed to peruse the phone for additional information. If the phone is password protected, however, then police must obtain a search warrant to access it.

- RELATED: OK for police to search cellphone if no password, says court

In the case that sparked the ruling, a man was arrested after a jewelry stand robbery and was found to have incriminating images and text messages on his phone. The court ruled that police were within their right to check his phone "in a cursory fashion."