This week Nintendo and developer 4J Studios launched a free Mario-themed DLC pack for Minecraft on Wii U, and now YouTubers are complaining that videos they've published featuring that DLC are being flagged for alleged copyright violation -- by Nintendo.

While Nintendo has a history of cracking down on fan-made YouTube videos featuring its games, this snafu seems accidental -- the Super Mario Mash-Up Pack DLC was promoted by Nintendo, but developed by a third party -- and potentially highlights weaknesses in YouTube's automated Content ID copyright protection scheme.

"We're hearing reports of copyright strikes on Super Mario Mash-Up videos," read a message published to 4J Studios' Twitter feed yesterday. "We were assured this wouldn't happen. Following up with Nintendo."

Based on one public complaint from a YouTuber, the ContentID system appears to be flagging Minecraft videos which feature sound copyrighted by Nintendo, including the music from Super Mario 64 -- which is included in the Super Mario Mash-Up Pack.