Under most circumstances, when you pay for someone to produce artwork for website or any type of publication, the purchaser owns the property. Otherwise whoever did the artwork for a logo etc could sell it in to someone else. You are employing someone to produce an item that you own the rights too. It's a standard contract. You also do not need to protect your work with copyright but it does make it far easier to prove ownership if at some point you need to take legal action. Just because an image does not display a © does not mean it's free to use. If you did not produce the image or work or did not purchase it, then it's not okay to use it and under Intellectual Property Rights, will be classed as theft. Unrelated to fireworks, I take many photographs for my own website and also use those images to sell the products afterwards. Having spent £1000's of pounds of digital photography equipment, software and a Macbook to edit them all, get extremely pissed off when I find images just copied and used by others without permission. Two years ago I found a Chelsea flower show gold medalist using my images in their brochure and I threatened them with legal action or payment for the use of the images. They paid up as it was cheaper than reprinting the brochure again or going to court. They could not have won in court as I had all the original unedited images to prove ownership. If they had asked before publication, I would have let them use them for free or provided alternative images provided a credit was given for the photograph. They blamed an external advertising agency and denied all knowledge. Also images altered from the original image as mentioned about removing a single pixel is totally wrong, as the theft has already occurred and without the original image the alteration could not have taken place. Having spent time, effort, I'd like to think skill and money to produce a publication/photograph, I fully understand why anyone would get pissed off with someone thinking they can just right-click and take someones work for free.