So I sent a message to the seller and told him that was a picture I took of my own collection and no one had asked permission to use it. Now, I've needed pics before and went to Google Images and grabbed a couple of random ones, so I figured this may have been the case with him too.
I read through the description of his listing and he said it was several hundred cans for sale. I warned him that someone buying cans would probably expect to receive the cans shown in the picture, especially since he made no mention that the pic wasn't his actual collection.
I'm not sure if the auction expired or he took my warning and ended it, but it soon disappeared after I sent the message to him. He never did reply to my message.
In the last four years, I've been asked if people can use pics from my site to make t-shirts, use in articles they were writing and even a couple of professors for their classes. I've said yes in every case. It's nice to know my pictures can sometimes be of use to others, but I certainly appreciate being asked first. :)