When I use a photo or illustration from Clipart.com, I write it out as: Deb Melian, CC BY-NC-ND, Clipart.com. I own the rights to the photo because of my subscription, but am not able to sell the clip art or any subscription, etc. But I can do so because I paid for that right. If someone takes a photo, and I have done this also, I notate it as follows: Deb Melian, Copyright 2012, All Rights Reserved. This is because I did the work, processed the picture, etc.
However, when one claims rights to a photo that they didn't purchase, subscribe, or even take, I can't see how they can claim rights to it, no matter if it is in public domain. The only way they can do so is if they have taken that photo, drawing, or illustration and modified it from its original format, then they can do so legally.
HubPages is very clear on giving credit where credit is due. There is even a HubPages LearningCenter Hub on: A Guide to Proper Image Use on HubPages https://hubpageshelp.com/media/Learning-Center-leg It is worthwhile for every Hubber to be acquainted with this, as our work does reach out across the World Wide Web.
So the long and short of your question is that, no, one should not claim rights to an image without giving credit to the site, person, organization, etc, as to where it came from, unless they themselves created it in the first place.