It's odd. There are small HITs throughout the day from CrowdFlower that use CastingWords and CW as keywords. Of course, every time I go to check it out (verifying transcriber's work matches with audio, no editing) I see this "Job Unavailable This job is no longer running. Sorry for the inconvenience. You can find more of our tasks by searching for "crowdflower" on Mechanical Turk." Think CW filters some stuff through CF before it goes to editing? Curious is all.
These used to be hits that CW put out on their own but it's basically just making sure the correct audio was transcribed. They turned these over to crowdflower a year or so ago.
Those hits disappear quickly because they're very easy to do. Basically, you only have to listen to the first few seconds of a few transcriptions and say if the text roughly matches the audio or not.