Recently, three spots on the first page (including #1) for our main KW ("widget software", over 2 million results) were captured by boiler plate sites which all seem to lead to the same company in India.
All three sites have a "Resources" link on the front page. Clicking "Resources" gets you to a page that has about 10 or so outgoing links and some Flash content. The Flash thing simply displays links to 140 or so internal pages, sequentially named "widget001.htm" and so forth. Those pages each have another 50+ outgoing links to directories, other sites (sometimes leading to the same company but for a different type of widget and again with a similar "Resources" section) etc.
As I understand it, the links in the Flash thing would be invisible to any spider. However, doing a "site:" search shows that all the "widget---.htm" pages where indeed indexed although there are no direct links found anywhere on the site.
Comments, anyone?