Compress client and shared files downloaded from servers, and that ends in "Saved/Packages", to avoid being able to read them too easily.

Some LZMA compression would already make it more painfull to steal code from other servers, and also reduce the files size.

Obviously some decompression will be needed when you're joining a server to populate the cache with the previously downloaded files.

I'm aware that there will always be a way to read these files, but it's already a good start in my opinion