In the past, blogging was a sport of literary kings and queens (journalists) where one respected the copyrights of others and infringement was a word rarely used in the blogging world but often used in anti-piracy cases.
How things have changed and there's a new sheriff in town. No, its not the wild west, it's the World Wide Web and they're dishing out settlement demand letters like Colt .45 slugs from a six-shooter. This is no laughing matter and should be taken seriously.
Here are some steps to take if you receive a settlement demand letter:
1). Relax, don't panic
2). Immediately remove the image or images from your site
3). Do not respond to the letter (this is not legal advice), audit your website to make sure you are not in violation or infringing on someone else.
4). Go here and here to learn more.
Don't know what Infringement means from a legal perspective, go to law school to find out. Cornell University Law School - Copyright Infringement