Security in OS X Lion is a big problem that not many people are aware of, and here’s why: your Lion computer contains the install/recovery disk on the internal drive. That means anyone with a basic knowledge of Mac and Lion can start up your mac and reset your passwords, thereby accessing your user accounts and all your personal data.Stokes informative post suggests ways to secure a Lion system including removing the install/recovery disk, setting a firmware password and/or using FileVault 2 (FV2). Stokes said, "Apple, of course, thought about this problem. Their own solution is to encourage you to use FV2 to encrypt all your data. Indeed, this is the BEST solution."
If you support Mac OS X you need to read this!