I've taken a street portrait photo (here) that I'd like to enter in a competition (the Sony World Photo Awards). I asked the man in the shop if I could take his photo, and he was more than happy for me to do so. I never asked him to sign any model-release document as it has very much an "off the moment" photo.
The rules of the competition state:
You confirm that each person depicted in the Entry has granted permission to be portrayed as shown.
and also says that:
[does not] violate any person’s rights of privacy or publicity
With this in mind, would it be valid to enter the photo? I'm sure I've been to exhibitions before which include a lot of impromptu portraits and street photography where I'd imagine that the photographer didn't go running after the subject with legal documents, but I could be wrong...!
(if it helps, I'm based in the UK)
It should be allowed for a competition, at least in most places in the US. It might be different however if the photo will be posted online, or published somewhere. The person's right of privacy would be violated if you took a photo indoors, for instance, or on private property, without them knowing. A photo on the street, or with oral consent, should be acceptable.
Bottom line is, try and figure out what they will do with the photo if you win. If they will publish it, you might email the guy asking for permission.
The First Rule is ALWAYS GET A RELEASE. I've seen a piece about a photographer shooting homeless people that gave each subject ten dollars to sign a release. You can always offer a print but make sure that you follow through!
That said, if you live in New York State you're in luck; NY State courts has repeatedly upheld that a person has no privacy on the street and any image used for non-commercial purposes are either art, journalistic or educational. That said, the reality is that the contest people are probably too paranoid to stand up for your rights as a street photographer (especially a large conglomerate like Sony) so go back to the First Rule.
It seems to me the answer is in the rules. "You confirm that each person depicted in the Entry has granted permission to be portrayed as shown.". That person did give permission, and you are able to confirm that they did. They don't ask for proof of any kind, so you don't need to supply it.
If the contest organizers were as paranoid as Mark Kalan suggests they would have put in a rule about needing model releases. The phraseology to me indicates that they won't get too upset about it.
A great difficulty in getting a person on the street to sign a release is that, while they may ok the picture, they balk at providing details about where they live etc. I did a project with the homeless over three months and the obvious problem with a release is that the people are homeless, address-less and reluctant to provide anything other than a street name. A signed release would be worthless. That they posed (to me) signifies permission - I am not an lawyer. Other than dressing the images up as art for a gallery (or changing them as to make the individual unrecognizable) my attorney advises that I can't publish them.