Strange backlinks

[Smileworks_Liverpool]

I'm a dentist and I keep getting my images turning up on pages where there are hundreds of images of dental procedures, linking out to dentists all over the world. It's not -ve SEO I don't think. There's just not enough of it to be that.

The images are linking back to me with follow links (but worthless) and the pages are indexed with low to moderate 10-30 DA (that's old DA)  and the new link explorer is showing them as worthless - so well done new link explorer!

I'm not worried they are harming my site because I'm sure they're being ignored by google.  But is there some evil black-hat scam going on that i'm not aware of?  Should I disavow? I don't care that they're using our images. They are watermarked and they are linking back to us.

I just don't understand the point of such a site either?  Is it a precursor to something more malevolent or spammy?

**So my question is - is this harmful or should I just let the crazy internet be crazy and not interfere?  **

I'm always wary of disavowing.

[EGOL]

These weasels steal images from my sites.  I believe that they hope to pull in traffic from image search by displacing your images on your site with your images on their site.  The goal is to produce adsense revenue using your images.  We file DMCA with Google when high traffic images from our site are being used this way.  We also file complaint with Adsense.  We've done this against hundreds of sites.

[Smileworks_Liverpool]

Thanks for that. This morning it says "the image has been removed for copyright reasons".  They've all gone.  Was that you? Thanks if it was.  I love cleaning up crap on the web. I disavowed them but they were literally gone this morning.

[EGOL]

That's great news.... but it wasn't me.  I didn't do anything.

It's possible that a competitor complained and they did a deep dive into the images being used by the site.

I have a competitor with images similar to mine.  Infringers are often taking images from their site and mine.  This compeitor is extremely aggressive about fighting infringement and they have solved a lot of my problems.  One of the few situations where I have enjoyed having them in my SERPs.