How to encrypt your Time Machine backups.How to encrypt your Mac external drives.So read on to learn about the macOS password protection features you need to use to stay safe. Think of it this way: if you let someone use your Mac, how can you be sure they aren’t looking through your private files? Your device can also get stolen - along with all the files on your hard drive. You shouldn’t consider this to be too cautious. If you’re serious about safeguarding your sensitive information, password protection on your files and folders is the most sensible way to go.