You click it to acknowledge the fact that you don't own it and you get this.
[R1] Forbidden Love
Your video may include the following copyrighted content:
"Above & Beyond pres. OceanLab-Lonely Girl (Original Mix)", sound recording administered by:
Ultra Records (MVR)
What does this mean?
Your video is still available worldwide. In some cases ads may appear next to your video. Please note that the video's status can change, if the policies chosen by the content owners change. Learn more about copyright on YouTube.
This claim does not affect your account status.
and if all else fails, there is a link underneath that to dispute the claim, even after you've acknowledge it.