Jesus christ, some people here obviously have serius issues with locked/unlocked doors. Who gives a shit? You guys piling on Milk Lizard should go outside more, breathe some fresh air and relax.
And yes, I do lock my doors, but I don't give a shit if someone doesn't, it's not like I care if I can go into their home.
Edit: I meant I lock my doors when I go out and I'm the last guy in the apartment, if my roommates are in, I don't bother. There's two autolocking doors on the way to our hallway anyway.