Comment by Tiberium

>allowed to have copyrighted content in the background

I might be wrong in your specific case, but generally YouTube doesn't just remove videos with copyrighted audio. Often copyright holders instead make it so that the video with their songs will have ads and they'll receive all the ad revenue.

https://support.google.com/youtube/answer/7002106?hl=en

"Depending on the copyright owner's Content ID settings, Content ID claims can:

- Block content from being viewed.

- Monetize content by running ads on it and sometimes sharing revenue with the uploader.

- Track the viewership statistics on the content.

Any of these actions can be geography-specific. For example, a video can be monetized in one country/region and blocked or tracked in a different country/region."