Don't worry, The notice is just part of the standard DMCA takedown process. IIRC it works kind of like this:

1. Ann makes a Video.
2. Bob posts that video somewhere.
3. Ann sees the video posted, but she does not want it to be posted, so she sends a DMCA takedown request to the hosting site (For example youtube).
4. Youtube takes the video down and sends Bob a DMCA takedown notice. Bob now has some time to send a counter-notice (I think it was called counter-notice, can't remember the exact name).
5. If the hoster recieves such a notice, it notifies Ann. It now waits for Ann to Sue bob.
6. If Ann does not sue, the hoster puts the video back up.