Image copyright infringing

Hi,
I've been contacted by a company called "[FONT=&amp]Science Photo Library"[/FONT] saying that I have used one of their images on my website.
They provided a proof of it, and are now demanding me to pay 400$ to settle it.
I removed the image, I don't care about this website, and I even removed the Wordpress installation on the website completely, so there isn't anything on it right now.
What should I do? I don't live in USA, should I be worried?

Thanks a lot!

tell 'em you got it from a bought compilation and have now dumped it.

You shouldn't be worried at all. I really doubt they will engage a lawyer to pursue someone that is not in the country, not making money of their image, and not even using it anymore.

Thanks guys for the help!

hmm
just remove image
why you had removed WP? so your site no more exists!
dont leave your full site for an email
its may be your competitive sites policy, so just don't give up. run your site again

You don't live in USA so you don't worry about that