This. Arguably, if you're not using full disk encryption, your adversary is someone that (at least) hasn't entered high school yet... ;-)
I'd add that it also does add a bit of "intent" (in the same sense that (quite easily pickable) door locks do -- if your child/friend/coworker unlocks your phone with your pattern, that's clearly crossing a boundary - more so than just looking at your unlocked phone.
I'd add that it also does add a bit of "intent" (in the same sense that (quite easily pickable) door locks do -- if your child/friend/coworker unlocks your phone with your pattern, that's clearly crossing a boundary - more so than just looking at your unlocked phone.