These are some high quality icons in the packs: Credit Cards Icon Set, HTML5 Geek Matt Icon, Halloween Icon Set, Social Bookmarks Icon Set (This icon set contains 47 icons and was released in July 2010). You need to go to the download page to get these files.
These icons should all be published under the Free License of the YOOtheme GmbH and there is a license file inside each of the packs explaining this further.
The Free License means that you can use the icons for personal, commercial and client projects. This includes software, web services, templates, themes, advertisements and videos.