Notice of DMCA removal from Google Search

A page on my site was falsely slapped with a DMCA notice. The entire message can be read here, which was from Google Webmasters. I run a MediaWiki-powered site that revolves around the people of YouTube, mainly of those who play Minecraft. The page that was targeted was one of the most visited page on the site because it ranked second or third on Google's search result. There has never been any infringing content anywhere on the page. What should I do? Am I suppose to fill out that "DMCA Counter Notification form" or is it for someone working for Altervista?

Yes, you should fill that form