OOPS! First of all, you haven't even MET the guy, but you claim that he carries his firearm exposed "24/7"! While you MAY have seen him a few times, when he wasn't wearing a suit or sport coat, I doubt VERY seriously if he carries an exposed firearm CONSTANTLY! Now, if you can honestly say that you've followed him from his home, and have observed him entering local stores with an exposed firearm, that might be a BIT different!
The majority of local/state/federal law enforcement agencies require CONCEALED carry for either off-duty or "plainclothes" assignments. If your new FBI neighbor is carrying exposed "24/7", then he is in direct violation of FBI regulations.
My guess is that you PROBABLY have seen him without his suit/sport coat when he was entering/exiting his vehicle on his PRIVATE property driveway. Perhaps he DOES, for one reason or another, want to "advertise" that he is armed....but it COULD be that he inadvertently exposes it because he has figured out that the majority of his new neighbors already KNOW that he's an FBI agent.
When I bought the house where I live, back in 1973, I had been a police officer for 2 years. While still in the moving-in process, I hadn't met ANY of my new neighbors so, as far as I knew, none of them knew that I was a police officer. Well, while UNARMED and unloading a rented U-Haul truck on the driveway, a pre-teen girl rode by on a bicycle. She saw me pushing a heavy cart up the driveway, and as she pedalled by, she yelled out, "Hi, Mister Policeman!" That caught me off guard, but I gave her a friendly "Hi!" in return.
After we had completely moved into the house, my wife and I introduced ourselves to many of the nearby neighbors. NONE of them knew that I was a police officer, but ALL seemed pleased to have us as new neighbors. After about one year, I learned that I wasn't the only law enforcement officer in the neighborhood, but that didn't surprise me.
About 3 years ago, when a young married couple bought the house next-door to ours, my first contact with the husband was just a few days after they had moved into the neighborhood. He was about to get into his car, and the first thing that I noticed was his EXPOSED handgun! I paused for a brief moment, wondering how to approach the situation, since I was NOT armed. I didn't know a THING about the man, but he was wearing a pair of suit pants, a white dress shirt and a tie. He had his suit coat draped over his arm as he stepped toward his car, and I instantaneously "registered" it in my mind that, even though he was armed, he didn't pose any threat to me. Well, he WASN'T a LEO, per se, but had a CCW permit. I stepped over to him, introduced myself, and learned that he was a prosecuting attorney for one of the local cities.
His CCW permit had been approved due to his prosecution activities involving gang members! We have since become very good friends, even though he is no longer a prosecuting attorney. His current "specialty" is within corporate law....and he no longer qualifies for a CCW permit. He says that he misses being armed!
Having spent 31 years in local law enforcement, I have dealt with FBI agents countless times. They're "different", that's for sure, but I've met several FBI agents that were decent folks. They learned a BIG lesson about thinking that they were "superior", just because they were FBI agents, when the Miami, FLA, shoot-out took place. That incident "humbled" them, and caused them to re-think their tactical deployment training.
I still think of the FBI as "College boys with guns", but they've come a LONG way since the days of J. Edgar Hoover (I still can't figure out why Hoover gave the ORDER that agents couldn't make left turns while driving FBI vehicles!).
Hopefully, your new FBI neighbor will turn out to be a "decent" person. On the other hand, it sounds like you have done some "generalizing" about him and his "24/7" style of exposed carry! Heck, you might find out that he only carries an exposed weapon "22/7"! (OUCH! I just bit my tongue!)