Hacker Images is https://www.flickr.com/groups/hacker-images/pool/ - a set of deliberately stereotypical staged photos of "hackers" placed on Flickr with a permissive license to see if news media would use them in articles, which they subsequently did, not knowing that the images were placed there deliberately for them to find and use.
E.g. this article:
Slate covered the "prank" itself:
- 2013-02: http://www.slate.com/articles/technology/technology/2013/02/hacker_photos_how_hacker_dojo_pranked_wired_with_hilariously_stereotypical.html
Subsequently there have been other similar images in the media, e.g. in this article:
- 2014-10-08: http://www.gruenderszene.de/allgemein/indieweb