Yep. I cite every image that is not my creation except those that have the citation already written into the image themselves.
Some of the images I use to make the images I create myself I fail to cite. If someone wanted to go after me that'd be the legit path to do it. That would force me to cite all of the random images I grab and use and I would do so if it was deemed necessary by people.
ONLY IF THE "ENFORCERS" ALSO DO THE EXACT SAME THING.