With the Lion release

"With the Lion release, Apple started to use an app store model similar to their gucci belts cheap iDevices. This allows a control point for getting updates, and offering a degree of quality control on the software that is offered," Permeh said.
"Additionally, in Mountain Lion, they implemented a new system called cheap gucci shoes Gatekeeper as a default protection mechanism. Gatekeeper ensures that applications that run must be signed by an appropriate signing vendor. This ensures that rogue applications do not run."
In the end, said Evans, the same very important rule of thumb applies to any cheap gucci belts piece of software, whether it's an operating system or an anti-virus program: stay current.
"When you can't stay current anymore, like when a manufacturer drops gucci free shipping support for an old OS," Evans said, "you absolutely need to upgrade if you plan on keeping your personal information safe."