For a paper we're writing, we need to use a small image of a popular, easily recognized piece of consumer electronics.
In previous drafts of the paper, a long time ago, someone made an image for the paper that ended up being the "headliner" image, i.e., the largest image that explains and outlines the subject of the whole paper. In it, because it was such an early draft and he was just trying to get the concept down, he clearly just googled the name of the piece of electronics and grabbed a random image he liked, cropped it, and put it in the larger image.
Now we're at the stage where we're actually going to submit the paper, but of course now part of our "headline" image is a random picture that we don't own, so I'm in a bit of an awkward position. Hopefully I can at least get the original composite image from the one who made our "headline" image (the image in the paper is flat so it can't just be "ungrouped" so I can remove/replace the offending part), but even then I don't know how to proceed.
So my question is, how can one use images in this way in a professional paper? Are you allowed to use anything on the internet as long as you credit it clearly? And if so, is there some way you're supposed to credit just a random URL?