I think most would know if they were asleep and someone starts fiddling with there hands...
The more problematic thing is if someone is passed out drunk, then its open game..I could VERY MUCH see people saying let's get this guy/girl drunk as **** so they pass out so we can get into there phone. Actually...make that a garuntee, i would be the one instigating it probably lol
You must have a pretty sad life if you would get someone "drunk as ****" just to get into their iPhone