Some is legally released, other, not at all.
The legal: http://rufftoon.tumblr.com/post/15847963673/very-very-tiny-korra-preview-from-0-19-to-0-31
(posted the link to the Tumblr post, just so I don't repeat the observation).
I won't post a link to any of it. I'm sure anyone too curious can easily find the material now: one second on the web, and there are copies making the round now. A lost battle, in terms of trying to control it all.
The leaker admitted to a few interesting things:
They got a screener copy from Viacom.
The screener was sent as part of licensing.
The leaker is in the UK.
The leaker is talking about lying low for a while, for there may be investigations ( NO REALLY, YOU THINK????)
I can only shake my head sadly. What is the "leaker" thinking? I've seen people lose their jobs for something like this! In the end, the leaker will be hurting his or herself, or the people around them. Is a few minutes of videos worth it all? No.
Please, if you're someone who know who the leaker is, please tell him or her to stop. It just isn't worth risking their work for that. Not just their current work, but future jobs as well, as their employment records will be tainted, especially if they want to stay in the industry.
or perhaps they don't care.