By uploading a video to YouTube you are giving them a special license to distribute the video. The license you choose in the video description doesn't apply to them. The title is incorrect in saying there is any kind of violation here.
A CC license doesn't give you the right to award Google all the rights it demands in Section 8 of the YouTube TOS. To try to do so violates the CC license, terminating your original agreement. Yeah, breaking a license term makes you liable.
Just to restate it, it is illegal to upload content to YouTube under a CC license because it's instantly an infringement. Of course if you have separate permission (or its yours) that's okay but that's not a CC license, that's a dual-license to you.
This is really common with user-submitted-content sites. Equally common is users not understanding this fact. Or caring.
Google has safe harbour. This is their users actions... But they {c,sh}ould be doing more to interrogate uploaders about the material source and licenses. Instead they just seem happy to let the DMCA do its work.