Plus, how can you claim privacy when it is being done on a public street? How does anyone have the right of privacy in public? There are security cameras all over the place. Are these cameras violating people's privacy. I don;t think so. If a landlord puts a camera in a tenant;s premises, then the landlord would be violating the tenant's privacy.But if a camera is on the street? or a supermarket? There is no privacy violation. The same thing is happening here. Anything you do in public is open to scrutiny.
Your analysis is flawed because you are focused solely on the initial act of compiling the photographic images rather than the subsequent re-use of those images in a manner that violates the law. From what Kepler has already said is the law in Quebec, and from what I know is the law in New York, it is that law that applies to the subsequent use that we are talking about in this thread. That subsequent use MAY violate the law depending on what the use is, its intent, its labeling, and whether it is deemed commercial or not. In this case the subsequent use would seem to be a possible violation of the law. You are confusing the "reasonable expectation of privacy" analysis with the "unauthorized use" analysis.
Of course surveillance video in stores and in public places is very common. It is usually done to monitor or create a record of possible criminal acts so that if and when they occur, the video can then be turned over to LE for investigation. There is no problem with that. But that is not what we are talking about in this thread.
And it should be noted that if these photographic images were turned over to Montreal LE, rather than being posted on Facebook, there could be immunity from any claim of defamation or violation of privacy. I will let Kepler speak to that issue more specifically under Quebec law, but in most US jurisdictions citizens have immunity for otherwise actionable defamatory statements or writings or publications, if they are made to LE as part or a criminal investigation or complaint. This immunity doctrine also extends to statements made to governmental agencies or boards, although the immunity may be qualified.
An example of this would be a zoning hearing to open a strip club across the street from daydreamer41's house. Daydreamer41 listens to the applicant's presentation, stands up and says, "that guy is a whoremaster who is running a brothel on the other side of town! He should not be allowed to open up a strip club across the street from my house!" Depending on the jurisdiction, Daydreamer41 would likely enjoy qualified immunity in the applicant's subsequent slander lawsuit against him. I could probably get it tossed in Connecticut on the grounds of a state common law doctrine we have (called the Noerr-Pennington Doctrine) that is strongly rooted in federal case law that in turn gives a very expansive definition to free speech that is made to governmental agencies, including local zoning boards. On the other hand, if Daydreamer 41 made the same statement in his local supermarket in front of 5 other people, he's toast on the defamation claim, which would be deemed slander per se because it implies a crime of moral turpitude.
The public policy behind all of these laws is to encourage citizens to freely communicate with LE/governmental agencies about issues effecting the public at large without fear of being sued for defamation or violation of privacy laws. That same public policy would not apply where citizens take matters into their own hands and post images on the Internet in an effort to privately chill or regulate some activity they do not like or approve of. The law will always favor and protect the citizen who brings criminal activity to the attention of LE rather than the citizen who acts on his own to stop it. Otherwise, the police would soon have nothing to do other than eat donuts if more and more citizens acted as private LE or private attorneys general.
One other thing: privacy laws are tightening across the USA, primarily due to the rise in identity theft, which is somewhat ironic especially in light of the recent Tiger Woods story and the unbridled vigor with which the press seems to go after such stories with really nothing being considered sacred or out of bounds. We have a new law going into effect on January 1, 2010 in Connecticut require redaction of all "personal identifying information" in documents filed with the Court (meaning social security numbers, dates of birth etc.) I just recently got a call about such a violation and I had to tell the person that the law is not effective until 2010.