How to manage your privacy with Lion’s “Resume” feature

With OS X Lion’s (s aapl) incredible success and high adoption rate, Apple customers and repair technicians such as myself are facing higher than usual rates of embarrassment thanks to Lion’s ability to restore your windows exactly as they were when an app was closed.

For example, if you were surfing a number of sites in Safari before you quit, those windows will return when you reopen the program. Some windows we may not want to share with others. I’m not talking just “adult” items, but, for example, a job search or dating site. Most Mac OS customers are used to having the more obvious digital debris of their life excised upon quitting an app. Unfortunately, in Lion, any application that supports resume (including most system apps, iWork and many more on the way) could unearth some embarrassing secrets.

There are a few quick solutions. When possible, close the Safari window or tab you’d rather keep private before you quit the application. Additionally, if you hold down the option key while choosing Quit from the application menu, or hold down Command+Option+Q, that will “Quit and Discard Windows” for this particular session.

If you forgot to do that and find yourself needing to close those open windows without launching the app, you can remove this information manually. To do this, first choose “Go to Folder” from the Go menu. Type ~/Library/Saved Application State/ and that will take you to the folder that contains your saved windows. If you want Lion to forget the last windows left open in Safari, look for and then delete that folder. That will remove the last session’s windows and tabs.

If you decide you really don’t like applications automatically remembering previously open windows and tabs, you can turn this feature off system-wide by opening the System Preferences application, and under “General” making sure “Restore windows when quitting and re-opening apps” is unchecked.

So the next time you go shopping for that wedding ring, remember that the next person who opens Safari might see the window and ruin the surprise. These tips should keep you out of hot water. And if you’re surfing for something else on your computer, the next person who has to use or repair it will thank you for keeping your private info private.