We do this all the time in MMO games, but it really stands out in the superhero-based ones. You have to learn to walk by citizens in need, or you'll never get anywhere. Every three steps you've got some poor slob who is on fire, being mugged, lost, trapped, injured, poisoned, imprisoned, or looking for their lost MacGuffin. By the time you free guy #3, guy #1 will have managed to end up on fire again. Protect the city? Hell, you could make a career out of just keeping a half dozen of them alive.
And yet I still feel a pang of guilt as I jog by NPC's in need. It's hard, but you have to remember that they'll never learn to take care of themselves if we keep solving their problems for them. If we want to see these people live on, then tough love is needed.
(Besides, you can't get any XP for helping them.)
Shameful plug: The hero depicted is Star on Chest. You can read his adventures here.