[Moved to Miscellaneous Forum - this isn't really a WordPress issue]
It’s being documented by numerous webmasters on various forum (see links below): Google Images redesign –implemented around Jan. 25, 2013– allows user to get hi-res version of any image without visiting the website where the image is hosted, resulting in significant loss in traffic from /imgres referral (which can be monitored from Google Analytics>Traffic Sources>Referrals>click on “google.com”)
This post is not about throwing stones or calling names, nor panicking, but simply documenting possible workaround. Solutions exist: see for example http://goo.gl/owaa4
And try to get hi-res version of those images: you’ll be redirected to the actual page of the original website where the image is hosted (NOT simply redirected to the home page of said website).
I believe it’s a kind of hotlinking protection, but I’m not sure how it works. Furthermore, hotlinking protection is a delicate tool to use:
1) You don’t want your image NOT to be indexed by Google Images
2) You need some bot to be able to access them: Facebook, Twitter (for their OpenGraph protocol), etc.
So I was wondering if anyone has some experience about this issue. Relevant links follow: