alt Hacker NewsThat's an argument you could make if police had to obtain warrants to access them. But they do not, at least in the US (things might be different in Canada where this happened, but I doubt it). Instead, they rely on rulings that there is no expectation of privacy in public. By the same principle, it's perfectly valid and legal for a civilian (or group of civilians) to set up an equivalent system to track police.
As you say this is Canada, so I don't particular care what the situation is in a totally different country where this didn't happen. Even in the US it's not as though "Warrants are for suckers" is just the law of the land, you and I and millions of others have and had the chance to weigh in on that. The fact that most people don't notice or care does make that sort of thing extremely difficult and frustrating, but that's not the same as it being futile or equivalent to "Guy sets up surveillance network to make a point and get media attention."