Keep in mind - the objective is not to shut down the sites, but make it difficult enough that your average person goes to legal sites instead.
Take me for example - I wouldn't have the faintest clue where to go find an illegal copy of a TV season on a "File Locker" - but I have zero problem finding legit stuff on iTunes or Amazon or Netflix.
I think the MPAA / RIAA have been very effective - in 2004/2005, there were a ton of places I knew about to download stolen content - but today - nope.