Once you point Hey!Watch in the direction of a YouTube video you want to download, it will get it, encode it in a format of your choice, and act as a super seeder for the first 12 hours, after which, the user and anyone else who has downloaded the video, can continue to share it with others.
Hey!Watch has really simplified the whole process of sharing a video over BitTorrent. Once you enter the YouTube URL on the site, it’ll fetch the video and create a torrent out of it. The only catch is that you must be using a BitTorrent client like Azureus or BitTornado, that supports the webseeding protocol.
How legal the service Hey!Watch offers is has yet to be questioned, but I doubt scraping video sharing sites like YouTube and offering videos for download, normally or over BitTorrent, is in accordance with those sites’ terms of service agreements. A while ago, Michael Arrington at TechCrunch was sent a cease and desist letter for putting up a YouTube download tool on his site.
The problem with Hey!Watch is that after you encode a certain number of videos, it asks you to upgrade your account, which costs, at a minimum, $4.99 a month. Free accounts are limited to 10 encodings per month, and all videos can’t be longer than 10 minutes. I guess I can see how something like this might be useful, but personally, I’d much rather just use the VideoDownloader Firefox extension or an application like PodTube. Everything doesn’t need BitTorrent.