google crawls and indexes images just like it does pages.
If you don't want it to, add a robots.txt to the root directory including the following.
Code:
User-agent: Googlebot-Image
Disallow: /
To get google to remove stuff it's already indexed you have to use it's removal tool...(you need to sign up)...
http://services.google.com:8882/urlc...&lastcmd=login