An option is, I suppose, to 'watermark' them in an image editor, with a copyright message across the image. Although it's irritating to look at, at least you could still contribute?

Talking of nabbing images, I turned up in a gallery about 3 weeks to see one of my pics of British Camp on a nice big photo-collage box canvas-thing. Lifted straight from TMA as that's the only place it was ever published.

They're out there, the Google-Imagist Movement!!!