Reminds me of something that happened to me... I take nature photos for fun and post them on my website and various photo websites over the years. A biologist for a National Park asked if he could use one of my photos on the cover of an internal publication. I thought that was cool, and sent him a high res file to use. Years later, I was googling something related and surprisingly one of the first links I click on was using my photo. I emailed that company and politely asked them to remove my photo, as I never gave them permission. I do more googling / image search, and find that the National Park put this photo on their Flickr page in a photo collection that said "these are all public domain images and feel free to use them anywhere." Alamy (stock photo website) now shows my photo covered with their watermarks and has it for sale ($20 for personal use and $199 for marketing). Sent a message to the NPS asking them to remove my photo from their Flickr public domain page, and never got a response. Oh well.