As I'm in the middle of still dealing with the rip of my ChickTech.net blog, the issue of content theft and copyright infringement are still heavily weighing on my mind. So I want to continue that discussion, touching on what you can do to specifically have infringing or stolen content removed from search engine indexes.
If you have a site or content ripped, you should make yourself familiar with the Digital Millennium Copyright Act (or DMCA). I won't go into a lot of detail on it (you can read a great article about the DMCA on Dan Richard's blog if you'd like to get some of the basics). Just know that this act is the reason you're able to request the removal of infringing content from search engine indexes, and simply put, why they can't ignore you if you properly submit a legitimate claim (otherwise they can lose their own protection under the act). Here are links to tell you exactly how to contact Google, Yahoo!, and MSN about removing copyright-infringing content from their search engines:
In some cases you may be allowed to submit your DMCA complaint via email. In others, you'll need to fax or snail mail it. Personally, I'm sending them via certified mail to at least Google and the infringing party's host and registrar (eNom). Creating a paper trail is generally a good idea if you're able to.
You can certainly check with other, smaller search engines as well. The DMCA offers search engines protection from linking to that kind of illegal content, but only if they promptly remove it if they're offered a legitimate claim of infringement (so it's in their interest to take you seriously). Of course, make sure you do really own the rights to the work before filing DMCA complaints. Otherwise, you may be the one finding yourself in legal hot water.