Hotlinking from flickr

I didn't want to do this, but now I see that some big blogs are using hotlinked images from flickr. They have a backlink to the picture on flickr. I was wondering if this is legal

 

what did you find illegal in this?

 

if the picture is the link back to the flickr page then all should be good...

 

Thank you guys, it looks like the picture doesn't have to be the link, but link needs to exist somewhere on the page and lead to page with picture on flickr.

 

Tim Ferriss is doing this on his blog, if he does that than I will do it too