One clarification I should make is that, as you've probably heard in the past, search engines—Google, Yahoo!—are cache things. They store them locally so that they can be called on more quickly. I don't know what their caching policy is or how long it lasts, but you can delete something and still have it being Googled for a period of several days or weeks. That's out of anybody's control but theirs. So that won't be covered in our policy. As long as a search engine caches, we can't do anything about it.
On November 6th, 2012. See this statement in context.