Some guy tells customer service about a customer with a gun

[Supertac45]

I see guys in the parking lot carrying guns all the time. It's what they are doing and what type of store, Gander Mountain or whatever?

[DefensiveCarry.com]

[Paymeister]

Would it be wrong to draw mine and yell " Some guy in here has one too!" and see if the guy pees himself?

I nearly did so when I read this! Great line!

[ccw9mm]

... some guy comes rushing into the store repeating in a loud but not shouting voice, "Some guy in the parking lot has a gun! Call the police."

What would you do at that point?

Probably very little, knowing "gun" is insufficient information to form any opinion about the degree of threat. I'd probably head off to the side to await finding out more, as the info came in, but that's only if the threat appeared credible. Depending when/where this occurred, it's highly likely the guy simply couldn't classify threat from non-threat very well. Hard to say without far more info beyond "gun."

[AZ Husker]

In Arizona, they'd say "so what"? Unless there's a threat, gun friendly states are very friendly and used to legal carry.

[Sheldon J]

I like the "more information please" reply, but the "I would show him mine and see if he p"s himself" is good to. Maybe they could be used in unison...

Could you give me more information please, was it drawn or did you just see it on him? Then the I'm not worried about it, and show him yours ,what would be cool is if he fainted, and then messed himself.