What is the license for photos published as the weekly featured photo? Do they become CC-by-SA like everything else on this site?
IANAL either, but I believe the images are not covered by cc-wiki. For instance, I can embed any image from the nytimes in an answer simply by linking to it, however that does not mean that image is now covered by cc-wiki.
We could probably clarify this on all sites by saying something like "images hosted on outside domains and linked to from this site are copyright their respective owners. all other images are copyright stack overflow internet services inc".
And then essentially the header image is just licensed to us temporarily for that week.
We don't have any intention to own the copyright on your images, nor do we have any intention of changing the desired license on your images (i.e. by somehow magically making them cc-wiki).
The current wording in the footer reads:
It also reads:
site design / logo © 2010 stack overflow internet services, inc;
I would expect it would go down the to the definition of what makes something a user contribution, and what constitutes part of the site design.
As a personal opinion, I prefer the interpretation that says that the user contribution is the post, which includes a link to a third party which hosts the image. As that externally hosted image is not part of any data dump, I wouldn't expect the licence to extend to that. Once it has been voted a contest winner, it is then incorporated into the site's design on a royalty free basis for a limited period.
I'll see if I can get a clarification on the view that stack overflow internet services, inc would take...
In addition, it's worth also remembering that images uploaded (as opposed to inserted as a link) are also covered by the imgur Terms of Service
In order for a photo to be selected, it first has to be posted by the user to meta (example), which is licensed as CC-BY-SA.
Instead of including the image in the post as content, you could only link to another site hosting the image. You could include a resized and cropped version in your post, and this altered version (but not the original) would be covered by CC-BY-SA.
I see no reason you must include any image in your submission, not even a resized/cropped version, but it certainly does make voting easier than just linking to elsewhere. :)
Including an image in the post rather than a link should be a significant difference — the former includes the photo as content in the post. It's the difference between taking a picture of a painting and handing out copies (this requires a license) versus telling someone the location of that painting within the museum (this information is not controlled by copyright).
(I am not a lawyer.)