Are home security guards allowed to scare you with a gun?

So it's in my neigbhorhood this huge house where a russian industrialist billionaire lives. Now i never met him and only saw him once in a lamborghini. But his house is a very impressively odd futuristic design. It's extremely huge, bigger than probably the white house. So i love looking at that house so i come a little too close to the gate and his security guard comes out of his little booth, this guy is like a 7 foot tall monster of a man with a strong accent and an ak-47 around his waist. He's like "don't come any closer". Wow, intimidating enough? Is the guy allowed to carry an ak-47 around his waist like that and scare the public if they get too close to a gate just to look at a house?