Why Would You Get Scared If You Saw Five Men In Black Masks Walk Towards You?

I'm not sure if scared would be the exact response I'd have, but there would definitely be a heightened state of alertness if your scenario played out with a group of guys in masks approaching, and it wasn't Halloween.

If anyone is oblivious to something of that nature and isn't at least mentally preparing themselves for a fight or flight response, then they deserve whatever comes of it. Colonel Jeff Cooper called this oblivious nature "condition white", and one should really never allow themselves to be in this mental state outside of their own home, especially in large, urban areas. It's not fear or paranoia, but rather, it's preparedness.