I get asked to come up with images for people when I am designing websites, so I thought it would be worth mentioning briefly about copyright issues.
This is really all you need to know.
If you did not create the images yourself or buy the rights to use it don’t do it.
There are enough places to get legitimate images for you to use, and if you just copy an image you found on the Internet, you run the risk of being sued for copyright violations. I know from personal experience, because I got fined for an old image that was not even on my site any more, but when they had run their scan that finds violations, it showed an unlicensed image and that’s all they need.
Some people incorrectly assume that if the image does not contain a copyright symbol it must be OK to use it? Not any more, consider everything you find that does not explicitly grant you some sort of legal use of the image to be off-limits.
One more thing worth mentioning is that regardless of where an image came from that is on your site, the responsibility lies with you as the owner of the site.