
These could be music, documents, or a folder.

It is thus a security measure for the program with regards to copyright restrictions.

The file or folder is in use and can't be deleted: Mostly happens when a file, e.g., a word document is opened and is in use.When deleted, their absence can cause your Mac OS to 'break.' It might not even be able to boot up. Your Mac system locks the file: Mac locks sensitive system files that are a must for its operations.
