Data mining what exactly? Unless you know what in the image, it's hardly interesting that a user with browser fingerprint X viewed some image with a random hash or name.

Sure it is, you can track the site it was hosted on and follow the fingerprint around the web. The image content isn't the juicy bit.

If I can see you viewed an image referred from /r/woodwork I might offer you some woodworking tools and drive up the conversation rate of my advertisements.

> The image content isn't the juicy bit

It is. The wealth of images alone, the sheer amount, from memes to vacation pics is worth so much now that image recognition is taking off.

I was perhaps too dismissive, it is certainly full of information. But I mostly meant for the moment the information most likely to be gleaned will be from referral links.