Question: I am not having much luck getting my intentions across here on meta so I will make this ridiculously short. This is related to the Unprofessionalism bullet-point in my [longwinded answer](https://skeptics.meta.stackexchange.com/questions/733/90-days-are-up-how-are-we-doing/761#761) to the 90 day opinion poll.

What guidelines do/should we have with regards to which types of images are fair game for me to edit out of questions and answers?

---

For the sake of discussion, here is the [same question](https://meta.stackexchange.com/q/92560/159491) asked at Meta.SO (with links to Sketpics.) There has also been handfuls of comments and chats regarding the topic. At this point I just want to know how I should act so I can go edit (or not edit) appropriately.

Answer: 
I have been leading my own crusade against many of the pictures - not about their relevance, which I am more relaxed about, and happy to defer to others - but about their credit and licensing.

If someone has a question about whether a particular photograph has been faked, it seems to my (non-lawyer) eyes to fit under the [criticism = fair use](http://fairuse.stanford.edu/Copyright_and_Fair_Use_Overview/chapter9/9-a.html) clause.

However, if someone has a question about ants eggs, inserting a random photo of an ant (or frame from a South Park episode) isn't fair use. In such a situation, the copyright owner must give permission to copy it. (Public Domain and Creative Commons licenses being the easiest way to get such permission.)

Simply having such permission isn't enough on a community site - we need to have a reference to that permission, so other editors know that it is okay. 

Finally, out of common courtesy, whether the license requires it or not, there should be a link back to the copyright owner - not merely to another web-site that have misappropriated an image themselves, but the copyright owner (and perhaps the original artist if they differ).

**In summary, every image should be associated with a link to the ultimate source and to the appropriate license, or an explanation of why it is okay to use without such a license.**
I'd like to mention [the image in this answer](https://skeptics.stackexchange.com/questions/1738/do-drug-addicts-stop-maturing-when-they-become-addicted/4764#4764) as an example of an on-topic image.