Which just makes it a generic ripping site because downloading YouTube videos is breaching the usage terms of the website in general.

"You are not allowed to: access, reproduce, download, distribute, transmit, broadcast, display, sell, license, alter, modify or otherwise use any part of the Service or any Content except: (a) as specifically permitted by the Service; (b) with prior written permission from YouTube and, if applicable, the respective rights holders; or (c) as permitted by applicable law;"