I was at a dinner this past weekend - my brother wanted to check out my new GNex. The face-unlock thought he was me and let him in. We're not twins but ok, I'll give you that since we're brothers, we've got similar facial features. GNex/ICS let him in 10 out of 10 times. However, then a friend of mine (does not look like me) tried it, and it let him in too (2 out of 10 times). I know - its gimmicky and not really good security. I don't plan on using it long term - just wanted to try it out. Just thought you guy's would be interested in my experience with it.