Is it OK to use Pinterest as a source?

Ah, technology - too often you come in as a white horse but damage us in ways we'd never expect. While I've been a long supporter of Pinterest I've recently noticed a problem with the social networking site. It's not an inherent issue with the concept itself, but rather with the way people are using it. 

On Instagram I've come across lots of posts where people hashtag Pinterest as the source of their photos - often on images that could easily be mistaken as their own. The #inspiration and #pinterest tags are the only thing included to indicate it's not actually their feet in the photo or their view out the plane window. Is this OK? It's only made worse by the fact that often times the photos belong to bloggers that I know and they aren't getting credited. There are whole Instagram accounts that feature nothing but inspiration photos. Some of them have tens of thousands of followers and don't credit where a single photo comes from. 

I'm guilty of having done similar things on this blog. When I do inspiration posts (like this one) there's a string of images and the source links back to my Pinterest boards. Each individual image also links back to the original pin it came from. But is this really an acceptable way to cite my sources or am I just as bad as the people on Instagram that stick in a cheeky #pinterest under their shot?

Tell me what you think. I'm on the fence on this one.

Photos from a selection on Pinterest.