In this particular answer, Dirty-Flow, is adding pictures as well.
Do they infringe the copyright protection and is this general practice on Sports Beta?
In my other meta question about copyright and fair use, I argued that the way that we had been using game images may not be fair use.
Fair use is a case-by-case analysis, so we can't make a blanket statement about images being copyright infringements. Even a case-by-case analysis is difficult and error-prone.
Our content is expected to be licenced as Creative Commons Attribution-Share Alike 3.0 (Unported). There are few questions to consider when deciding if an image is appropriate for Stackexchange.
Does somebody own copyright to the images?
Has the owner issued a licence for us to use the photos that is consistent with the Creative Commons Attribution-Share Alike 3.0 (Unported)?
Even if somebody owns copyright to the images, and has not granted a licence for us to use the photos, our use could still be fair use, but that is a case-by-case analysis that needs to consider 4 factors:
Things that tend to sway the balance towards a finding of fair use are:
Wikipedia handles this by using a standard that is much much stricter than fair use for deciding whether or not to use copyrighted material in their encyclopedia, so that they are always on the fair-use side of the line.
Regarding Dirty-Flow's answer, in my opinion, this entire answer (not just the images) is a copyright violation that would not be covered under a fair use exception, and we shouldn't pass it off to our readers as licenced under Creative Commons Attribution-Share Alike 3.0 (Unported).