Via: news.techworld.com/security/3334788/apple-filevault-2-encryption-cracked-by-forensic-software/
If your computer is on and logging-in was automatic your full-disk encryption used with OS X Lion may not be that safe.
It may only take “minutes” to recover the password.
Note: Microsoft’s BitLocker encryption and the open source tool TrueCryp won’t save you.