I think its showing that you have stuff matching 3rd party content . and i think you can acknowlege it so you womt get a strikeHello as I wrote, I saw new tab "Content ID" when I click on it, it redirect me to the home page... It 's not copyright notice...
Yeah, that's right, I dont have any copyright problem, copyright problems are on the another place,,,It's a new feature YouTube is adding. Still not enabled.