One of the newer security features in OS X Lion and Mountain Lion is Gatekeeper. Gatekeeper helps screen out malware like a doorman screens out people trying to get into an exclusive nightclub.
Gatekeeper can also cause headaches if you use software that isn't from a trusted source such as the Mac App Store. To learn how to use Gatekeeper and how to keep from getting the dreaded "Damaged Software" error when you try to load an app from the Internet, check out our Mac OS X's Gatekeeper Security Feature Explained article.
Has Gatekeeper saved you from a malware infection? Let us know in the comments section below