Comment Last I checked.... (Score 4, Informative) 174
Last I checked on my Samsung Galaxy SII (with ICS 4.0.3), the "Face Unlock" feature was aptly labeled as "Low Security, Experimental".
The only item marked as "High Security" is the password option.
I don't have an S3, but from what I've read the UI/OS version is pretty close at the moment (4.0.3 vs. 4.0.4). And I do believe, correct me if I'm wrong, that "Face Unlock" is still labeled the same.