Artists Legal Outreach has written this very interesting article about the LEGALITIES of Photography.
"I'm a photographer
Photography is the oldest part of the Act, unfortunately, technology has evolved considerably since the Act was written. "
If you are taking the photo for yourself you will own the copyright. However, unlike other cultural work, the copyright of a photo belongs to the person who commissions, and pays for the photograph, and not the photographer. A lot of photographers work likely falls under this rule.
So if you want to keep your copyright, it’s crucial that you assert it. That means you should indicate on the receipt that you retain the rights, stamp it on the back of the photo, or put it in a contract. If you are being commissioned to take photos for someone, make sure to read the terms of the contract carefully to see if you’ll retain copyright or not. Usually, you can negotiate with people. Check out CAPIC’s copyright page. Scroll down to the FAQ. There are sample invoices there and lots of information.
What can I take photos of?
Photographers may take photos in public spaces, which include the sidewalk and buildings, but likely don’t include shopping malls and private dwellings.You’re allowed to take photos as long as you are shooting from outside the building and you’re on a public thoroughfare. There are some real concerns about limits being imposed on public photographers particularly in theUK.
Am I allowed to take photos of people in public?
Yes, but be aware that privacy and personality rights exist, which means there may be consequences. Some people may not like that you have taken their photo, and try to stop you. Put another way: you may photograph street life, but not a life on the street:
"Since the right to one’s image is included in the right to respect for one’s private life, it is axiomatic that every person possesses a protected right to his or her image. This right arises when the subject is recognizable. There is, thus, an infringement of the person’s right to his or her image, and therefore fault, as soon as the image is published without consent and enables the person to be identified....The public’s right to information, supported by freedom of expression, places limits on the right to respect for one’s private life in certain circumstances. ......a photographer is exempt from liability, as are those who publish the photograph, when an individual’s own action, albeit unwitting, accidentally places him or her in the photograph in an incidental manner. ...One need only think of a photograph of a crowd at a sporting event or a demonstration. (Aubrey v. Éditions Vice‑Versa,  1 S.C.R. 591)
The key to the premise is the "background", not the "public". We have privacy rights even when we're in public. If you photograph someone in public such that they "step out of the background", as it were, or distinguish themselves from the crowd to become the subject of the photograph, you will need to get a release.
There may also be some limits - you cannot for example take a photo of the Eiffel Tower at night because the light designer does not permit it (without paying a license fee).
Bear in mind that if you take photos in public spaces, using a telephoto lens may not be allowed, since the subject of the shot has privacy rights. If you’re using a telephoto lens, you might need to get a written release.
Legal tip: why a release is a good idea
Getting a release is a good idea when you work extensively with people and where your work apears commercially. There are different kinds: model release and location releases being the most common. It is also important to note that children (minors under age 19) and people who are incapable cannot sign releases only their legal guardian's can. Always to confirm in writing that you have their permission in cases where you do not have a formal release. Releases do not mean that you will not be sued - they provide a defence to a claim. Sascha Baron Cohen was sued by the subjects in the film Borat who did not like how they were portrayed. Though they were unsucessful, partly as a result of the releases in place, it did not stop them suing.
Q: I found a bunch of photos in Value Village and I want to use them in an installation. What do I do?
A: It’s risky to use work when you don’t know where it came from because the Copyright Act requires you to find the original owner or at least make reasonable efforts to find the owner. If you run them in the installation, you run the risk of someone seeing the installation, and claiming they own the copyright. Even in cases where photos are found or presumed abandoned, copyright may an issue.
An added twist is that because ownership of photos rests with the person who commissioned or bought them, it can be difficult to figure out who actually owns them. In a recent local story one playwright found out the hard way. James Long tells his story Clark and I.
Q: I’m a photographer, and in the process of selling a photo to an organization. They have given me a contract to sign, and it isn’t ok with me in some ways. Can I change it? One thing that definitely isn’t ok is that the contract states I won’t be able to display the purchased photo under my own name, or sell the photo again. What do I do?
A: Often contracts of this sort are “take it or leave it.” A purchaser often wants sole control over the photo, and if they have concerns that the photographer might sell multiples, they take this contractual approach to limit how the photo is distributed, especially if they’re using it for branding, and they want to have a unique image for their business. There is no specific solution – it’s all about exactly what you want to change, and how you negotiate. If you want to use the photo you are selling for something like a personal portfolio (i.e., for something that is not going to be distributed widely) you might have more leeway in changing the contract, than if you want to sell the same photo to another organization. It is important to write your concerns into a contract, or into a cover letter, in which you address your copyright concerns and clarify which rights are being transferred. For example, if you only want to use the photo in your portfolio, you would state in the letter that, “the following terms are non-negotiable; I retain the right to use the photo for non-commercial purposes, and if the photo is displayed, I will receive credit for the photo.”
Q: I upload many of my photos to Flickr. One day, I noticed an advertisement using my photo. No one contacted me to ask for my permission to use the photo. What do I do?
So how does this apply to you? According to FlickR: Photos and/or images found on Yahoo! Images or Flickr are the property of the users that posted them. Yahoo! cannot grant permission to use third party content. Please contact the user directly.
Depending on the type of license you assigned to the picture that ended up in the ad, this use of your photo, without your explicit permission, might be perfectly legal. If you tagged your photo with only an Attribution License, so long as somewhere on that ad there is some mark giving credit to you, the photographer, the ad is probably not in violation of copyright. And the person or corporation who made the ad was able to use your photo without going to the trouble of contacting you. Maybe this is just fine, and it’s what you intended. However, if you did not want it used for commercial purposes you might want to reconsider your choice of license. If you are not posting to FlickR you might also want to consider putting specific information on your website so that if an image shows up on a Google Image search people will know whether you are okay with how the photo is used.
But what if the photo in question has someone else in it – say a good friend of yours, and she is not at all pleased to find her image plastered all over bus stops. If the people who made the ad didn’t contact your friend and get permission to use her image for commercial purposes they made a mistake, and your friend can pursue them legally.
Q:I was assisting a photographer at my internship and the last 10 minutes of the shoot he said I could go in there and take some photos. I took several and he liked them, it was time for production and editing and to my surprise the photo that was used for online distribution was the one I took, I was excited, but I wasn't credited for anything, I didn't mind because I knew I was just an intern and it was all a learning process, but should I have said something? I didn't wanna burn any bridges or step on anyones toes, but what could I do in a situation like that?
A: Whether students or not we will all have to deal with an issue like this at one time or another. When you agree to work for someone as an intern, or an assistant, you should make sure that at a minimum if there is an opportunity to take the photos that you get the credit. Professionally, another photographer should respect your seeking the credit (if not a fee). Claiming someone else's work as your own is as clear a violation of copyright.