If you're on public property, you have zero reasonable expectation to privacy. People can, and will, take photos of you whenever they want. You can make rude gestures if you like, but you can't stop them from taking pictures - the law is very clear. If you even touch the lens of the camera to cover it can be considered assault. Same thing goes for taking photos of Police in action - provided you are on public property you may take photos of anything you like - nobody can ask you to delete photos either after you have taken them, they are private property. If you want to understand more about the laws that surround photography, this is a good site to get an understanding of the laws in Canada:
http://ambientlight.ca/laws/
Since you're so angry about it... I hope many people take your photo and post them online