Google provides definitive instructions for: (1) removing sensitive pages from Google's search results, and (2) preventing pages from being indexed by them in the first place:
Preventing content from appearing in Google search results
Note that, with the exception of Google, Yahoo!, MSN, and Ask, you should expect both your meta tags and requests for page removals to essentially be ignored. Worse, many of these "rogues" are based overseas where you'll have little or no legal recourse in the event of a problem.
Relatedly, don't assume that your private pages are "safe" from being Google-indexed because you have no links pointing to them or you haven't submitted them. Search engines have many, many ways of finding new pages -- e.g. a visitor's Google toolbar auto-submitting them, a competitor submitting them for you, links from sites you don't control, etc.
Confidential info should always, always be password protected -- or never placed online at all.