Re: Usage rights?
I guess you have to assume that the website owns the copyright since it doesn't state otherwise. Nothing in the image properties when you download them.
I found that when you try to download the image you don't necessarily get the image you are after. when I downloaded the photo I got a different one saved than what was on screen, tried again and got a different one again. So it looks like it continues to generate them in the background even if you don't refresh the page. Even going to page info and then media in Firefox showed a different image each time.
So screen shots appear to be the only way to get a copy of the images, which suggests they don't want you re-using them.