Hate to be the monkey wrench here, but most of us were presuming -- until fairly late in this thread -- that this person is carrying legally -- and wasn't about to rob the 7-11...
I'd eyeball him VERY carefully -- with my hand on my 640 .357 in my right pocket -- which I practice producing in one-half of one second...
He could be about to use that pistol on me -- and you can't always tell "thug" from "law-abiding citizen".
Ted Bundy was one of the most innocous looking people in the world.
Actually, it's this type of situation that led me to get a CCW in the first place.
One of the conditions of S.C.'s CCW law is..."It remains concealed -- and if it shows in ANY way, the law is being broken..."
The police are the ones to sort this one out...
(Of course, at a restaurant sometime back, I had to tell an auxilliary police woman I knew that she was "showing" and wasn't as plain clothes as she thought...)