viral - 11:14 pm on Oct 27, 2013 (gmt 0)
Sevencubed is right. If you really want the content to be gone use 410. Google keeps coming back for a while looking for the old 404'd page. 410 explicitly says forget about this page.
However you really need to use them even more carefully than 404's. A 404 you can come back to and 301 at a later stage. 410's you can't.