The image you see displayed on G+ is not the original image. So what if you can save it directly with no metadata. Even if there was metadata all you have to do is download the image, (which is the original image and contains all the metadata) and strip it out.
Finally however, I would say, that companies like Google and Flickr could show that they at least subscribe to the notion that peoples creative work is entitled to be respected, which they and many other internet sites currently don't.
I have had a few examples of my images being used without my permission. In each case I have sought and gained redress. .