A recent article about street photography suggested pointing the camera into the sun and taking silhouettes as "a great way to create a dramatic effect while maintaining the anonymity of your subject".
I downloaded the picture, adjusted it in photoshop to show that the anonymity was not kept and posted that to the comments.
The photographer complained, "Please don't modify my photos without permission".
My impression is I don't need her permission as it's fair use. I was using it to comment and educate. I'm not trying to sell it. I'm not depriving her of any income (no one is going to want the modded version. The modded version is not a good picture because with the adjustments it's no longer interesting. It just shows that anonymity was not kept. Both pictures are also relatively low-res (web pictures).
Is it "fair use" or should I take it down?
note: I could have also just screen captured it (2 buttons on my iPhone) and then edited it in the built in photo editor. The point being it's not difficult or rare to edit photos in 2015.