“Over the upcoming holidays, members of my extended family will be sharing my Mac to check their email and surf the web. I have some files that I’d like to keep hidden from them. I’m particularly concerned that some of these files will appear in Spotlight. Is there any way to hide them?”
I can recommend a few options.
The first is to force them to use your Mac’s Guest account. To ensure that it’s an option when your Mac starts up, launch System Preferences, select Users & Groups, click the Lock icon and enter your username and password to unlock the preferences, select Guest User, and enable the Allow guests to log in to this computer option. Additionally, click on Login Options and be sure that Automatic Login is off. If you then log out of your account, the login screen will display at least two accounts – yours and the Guest User account. To use your Mac your relations will choose that Guest User account and then do their business via Safari and webmail services.
If, for reasons best known to you, you want to let them use your account you can keep these files on another volume. If you don’t have a lot of sensitive files you could copy them to a USB flash drive, delete them from your Mac’s hard drive, and then tuck away that flash drive until the in-laws leave. At that point, copy them back on to your Mac.
Or you could password protect those files by placing them in a folder and then creating an encrypted disk image of that folder – a process I described a few years ago in this very column.
If you’re specifically worried about your files appearing in Spotlight, just gather them together into a folder, launch System Preferences, select Spotlight, click the Privacy tab, and drag the folder into the Spotlight window. This prevents Spotlight from searching the folder.
There’s one problem with this solution, however. If your precocious niece is familiar with the workings of the Mac OS (and frankly, what precocious niece isn’t?) all she need do is launch that same preference, click the Privacy tab, and take a gander at what you’ve chosen to hide (the little sneak!).
Fortunately, you can thwart her. Just create a folder for the files you wish Spotlight (and your niece) to keep its nose out of and append .noindex to its name (My Secrets.noindex, for example). This tells Spotlight to exclude the folder and its contents from searches. And, best of all, any folders with this extension will not appear in Spotlight’s Privacy tab.
by Christopher Breen, Macworld