I've tried putting in some of my content and seeing if it shows up anywhere - dead end.
When I set up analytics, I set a separate profile with a filter that shows only page views where the hostname is not my site. This profile shows Google Cache views, Google Translate views and sites where the content has been copied and they left the analytics code in place.
You'll likely see a bunch of views via Translate where someone translated multiple pages of your site. A few days later you might see that your content has been posted in some foreign language on other sites. That's why you can't find your content elsewhere via a normal search at present. It's likely to have been translated by the spammers before being used.