I'm not an expert on the Ontario Highway Traffic Act. I do know they run RIDE programs in which they pull everybody over at random. I shouldn't say everybody. They fill it up, and they talk to those people, and then when they're finished with them they bring in some new people. I am aware of several court cases in which the police, as part of an anti-drinking and driving campaign, have started to pull drivers over at random—generally in the wee hours of the morning in the party section of town—and they're doing it to check for sobriety. That's their reason, and that's been upheld by the courts.
On September 27th, 2016. See this statement in context.