There's a reason why my department requires LEOs to carry their weapons concealed when off duty, it's to not cause alarm. That's the fastest way to have an appointment with internal affairs, to let one of the sheep see your firearm and get alarmed.
What I can't comprehend is when people who OC are surprised when someone calls the cops on them or are alarmed. That's something you should expect if you OC. Even though I'm a LEO, I can't OC because my department SOP prohibits me from doing so regardless of whether or not I'm wearing my badge.