Another detail of that scheme: Wikipedia actually does not do (correct) attribution on their site (no attribution next to the images. So if you mirror/copy Wikipedia content, in germany you will be sued by "photographers" who won't enforce their attribution on wikipedia but will on your site (to make a profit, see above).
More recent versions like CC-BY-SA 4.0[1] explicitly say that it may be reasonable to attribute via a hyperlink.
Older licence versions do not have this line, but even then, it could be argued that Wikipedia itself is not infringing because attribution is still provided as part of the same work (considering the whole of the German Wikipedia as the work), rather than on an external site.
Unless German courts have already ruled that attribution has to be next to the image?
1. https://creativecommons.org/licenses/by-sa/4.0/legalcode#s3a...
"Order of Parental Glory" [1] is one of the examples. Strangely enough, many of the examples of inline attribution is for images from kremlin.ru, meaning there's probably some kind of agreement that mandates inline credits back in the days, but no longer anymore.
If you don't have JavaScript enabled, it's still displayed when you view the full-size image, but it loads a different page to do so.