TOLORS wrote:

4.1 Disable “See Inside” or restrict sharing
Some users want an option to prevent Scratchers from looking inside their project and using their artwork, scripts, or sounds. However, the core ideas of Scratch are "Imagine, Program, Share." By sharing a project on the Scratch website, you are allowing others to see the code and potentially remix or reuse the data inside, as long as they give credit. That being said, please use the Report button on any project that uses content from another Scratcher without giving credit to them. If you do not want other users to see inside your project, then do not share your project on the Scratch website.

(source)

b]4.1 Disable “See Inside” or restrict sharing
Some users want an option to prevent Scratchers from looking inside their project and using their artwork, scripts, or sounds. However, the core ideas of Scratch are "Imagine, Program, Share.“ By sharing a project on the Scratch website, you are allowing others to see the code and potentially remix or reuse the data inside, as long as they give credit. That being said, please use the Report button on any project that uses content from another Scratcher without giving credit to them. If you do not want other users to see inside your project, then do not share your project on the Scratch website.

Restricting sharing so that only certain users can view the project is also not going to be implemented. It is important for projects to be publicly shared for everyone to see so people can report them if they are inappropriate. Only allowing certain users to view projects could increase the chances of inappropriate projects being shared on the website. ”Unlisted projects," similar to a YouTube feature, will also not be implemented for the same reason; for more information, see this post. It could also be used for private messaging; for more information, see #7.1 on this list.