The "title" attribute of each image contains a link to the source. The second image (lightning) that I've randomly followed is licensed CC0. (It's an interesti

The "title" attribute of each image contains a link to the source. The second image (lightning) that I've randomly followed is licensed CC0. (It's an interesting question, though, whether copyright protection can be expected to "scale" down to a 3×7 pixel subset of an image. At what point does it stop being a derivative?)